Fact-checked by Grok 2 weeks ago

Nipple

The nipple is a protruding anatomical structure composed of smooth muscle fibers and erectile tissue located at the center of the areola on the human breast, serving as the outlet for milk secreted by the underlying mammary glands during lactation in females.^[1] Nipples develop identically in male and female embryos from mammary ridges around the fifth week of gestation, before sexual differentiation occurs, explaining their presence in both sexes despite males lacking functional lactation under normal conditions.^[2] Structurally, the nipple features 10 to 20 pores corresponding to the terminal ducts of the lactiferous system, which converge milk from glandular lobules, and is surrounded by Montgomery's glands that secrete lubricating oils to protect against irritation during nursing.^[1] Its dense innervation by sensory nerves, including branches from the fourth intercostal nerve, renders it highly sensitive, functioning not only in infant suckling reflexes but also as an erogenous zone in adults due to autonomic responses involving oxytocin release.^[3] In mammals broadly, nipples vary in number and position by species—typically multiple and abdominal in quadrupeds like dogs for litter access, but paired and pectoral in primates—to optimize offspring attachment and milk transfer, reflecting evolutionary adaptations to reproductive strategies.^[4] Pathologically, nipples can exhibit inversion, a congenital retraction affecting up to 10% of individuals that may complicate breastfeeding or signal underlying ductal issues, while piercings and cultural modifications highlight its symbolic role in human adornment, though these carry risks of infection or necrosis if vascular supply is compromised.^[5]

Etymology and Terminology

Origins of the Term

The word nipple entered English in the early 16th century as a diminutive form of neb, an Old English term denoting a beak, nose, or snout, reflecting the anatomical protrusion's beak-like shape.^[6] ^[7] Earlier variant spellings included neble and nible, with the first known attestation around 1510 specifically referring to the mammary gland's protuberance through which milk is discharged.^[7] This derivation aligns with Germanic roots in Proto-Germanic nib-, emphasizing pointed or projecting features, and distinguishes the term from Latin papilla (meaning nipple, adopted later in scientific contexts for similar structures).^[6] ^[8] By the 1530s, nipple had solidified in usage for the human anatomical feature, initially in medical and descriptive texts, before extending metaphorically to mechanical small projections, such as pipe fittings by the 18th century and nursing-bottle mouthpieces by 1875.^[6] ^[9] The term's adoption avoided direct borrowing from classical languages, favoring a native English evolution that prioritized descriptive morphology over foreign anatomical nomenclature prevalent in Renaissance scholarship.^[6] No evidence suggests influence from non-Indo-European sources, underscoring its organic development within English vernacular traditions.

Anatomical and Medical Terms

The nipple is anatomically designated as the papilla mammae in formal nomenclature, referring to the protruding, cylindrical or conical structure composed of smooth muscle fibers, erectile tissue, and ductal orifices that facilitates milk ejection in females.^[1] The surrounding pigmented disk of skin, known as the areola mammae, contains sebaceous glands (glands of Montgomery) and exhibits radial folds, varying in diameter from 1.5 to 6 cm in adults.^[3] Collectively, these structures constitute the nipple-areolar complex (NAC), a critical anatomical unit in breast surgery and reconstruction due to its vascular and neural integration with underlying mammary tissue.^[10] In medical contexts, the nipple's ductal system includes 15–20 lactiferous ducts opening at its apex, termed ostia ductuum lactiferorum, which converge from the breast's lobular parenchyma.^[11] Variations in form yield terms such as mammilla plana for flat nipples, mammilla invertita for inverted or retracted forms where the nipple inverts into the subareolar ducts, and polythelia for supernumerary nipples arising from embryonic mammary ridges.^[5] Athelia denotes congenital absence of the NAC with underlying breast tissue present, while amastia indicates complete agenesis of breast tissue including the NAC.^[1] ^[11] Histologically, the nipple's epithelium transitions from stratified squamous to columnar within ducts, supported by fibromuscular stroma rich in sensory nerve endings from the fourth intercostal nerve.^[12] These terms derive from Latin roots, with mamilla (or mammilla) signifying the nipple as an extension of the mammary apparatus, emphasizing its role in both lactation and erogenous sensation across sexes.^[13]

Embryology and Development

Prenatal Formation

The prenatal formation of the nipple occurs as an integral component of mammary gland embryogenesis, independent of sex differentiation and driven by ectodermal-mesenchymal interactions. During weeks 4 to 6 of gestation, mammary-specific progenitor cells differentiate within the surface ectoderm, leading to the development of paired mammary ridges—also termed milk lines or crests—as longitudinal thickenings extending bilaterally from the axilla to the inguinal region around day 35. These ridges represent the primordial anlage for mammary tissue across mammals, though in humans, all but the second (pectoral) pair regress by default, leaving localized mammary placodes that thicken and mark the site of future glandular development.^[14]^[15] The primary mammary bud emerges from placode invagination into the underlying mesenchyme by the end of the first trimester (around week 12), forming a bulbous structure with central epithelial cells surrounded by basal layers and a mesenchymal envelope. This bud elongates and branches into secondary epithelial sprouts during the second trimester, which canalize to establish the initial lactiferous duct framework by approximately 6 months' gestation. Nipple morphogenesis specifically initiates with epidermal thickening and depression into a shallow mammary pit, suppressing hair follicle formation via signaling pathways such as parathyroid hormone-related protein (PTHLH), while mesenchymal proliferation delineates the nipple's contour.^[14]^[15] In the third trimester, repeated branching from secondary buds generates 15–25 terminal lobules, with ducts converging to open at the base of the mammary pit; the areola differentiates concurrently by the fifth month through pigmentation and glandular element integration. The fetal nipple remains largely inverted within the pit, everting postnatally via subepidermal mesodermal expansion and smooth muscle differentiation around weeks 12–16. This process is hormone-independent in early stages but influenced by placental factors later, yielding a functional nipple-areolar complex in both sexes at birth, with ducts rudimentary and capable of transient milk secretion (witch's milk) under maternal hormone withdrawal.^[14]^[15]

Lifespan Changes

In newborns, exposure to maternal estrogens crossing the placenta often causes temporary nipple enlargement and breast budding in both sexes, affecting up to 70% of infants, with possible milky discharge known as witch's milk from the nipples.^[16]^[17] This phenomenon typically resolves within 2-6 weeks as hormone levels normalize, leaving nipples flatter and less prominent during early childhood.^[18] Minimal morphological changes occur in nipples through pre-pubertal years, with stability in size and projection until hormonal surges initiate puberty.^[19] During puberty, nipple changes follow Tanner staging in females, beginning with breast bud formation where the nipple elevates and the areola enlarges and darkens (stage 2, typically ages 8-13).^[19] Progression involves further projection (stage 3), a secondary mound of the areola and nipple above the breast (stage 4), and maturation to a smooth contour with only the nipple raised (stage 5).^[20] In males, analogous initial budding occurs but regresses post-puberty, resulting in relatively flat, minimally projecting nipples without significant areolar expansion.^[21] In adulthood, nipples remain stable absent pregnancy, but during gestation, hormonal shifts cause enlargement, darkening of the areola, swelling, and prominence of Montgomery tubercles (sebaceous glands on the areola) to facilitate breastfeeding.^[22]^[19] These adaptations, driven by rising progesterone and prolactin, often include nipple hypersensitivity and colostrum leakage by the second trimester.^[23] Post-lactation, partial involution occurs, though some enlargement may persist; repeated pregnancies can lead to cumulative changes like increased pigmentation.^[24] With menopause and aging, estrogen decline contributes to nipple inversion or flattening in some individuals, as shortening milk ducts pull the nipple inward, alongside areolar shrinkage that may render it nearly indistinct.^[25]^[26] Nipples may also deviate caudally (downward) due to loss of breast tissue elasticity and glandular atrophy, with reduced projection and occasional wrinkling from connective tissue changes.^[27]^[28] These alterations are more pronounced in females but occur similarly, albeit subtly, in aging males owing to shared tissue remodeling.^[29]

Anatomy

External Structure

The nipple is a raised, cylindrical or conical projection of skin and underlying connective tissue situated at the apex of the breast mound, serving as the external outlet for the lactiferous ducts.^[1] In adults, it typically measures 10 to 12 millimeters in diameter and 9 to 10 millimeters in height, though dimensions vary individually and with physiological states such as pregnancy or arousal.^[1] The surface is covered by stratified squamous epithelium, often exhibiting a wrinkled or ridged texture due to underlying erectile tissue, and features 15 to 20 small openings at the tip corresponding to the dilated ends of the milk ducts.^[1] ^[3] Surrounding the nipple base is the areola, a circular, pigmented region of skin averaging 3 to 6 centimeters in diameter, which contains sebaceous glands (tubercles of Montgomery) that secrete lubricating oils, particularly prominent during pregnancy to protect the nipple during lactation.^[1] ^[30] The areola's pigmentation ranges from pinkish to dark brown, influenced by genetic factors and hormonal changes, and its surface may include fine hairs and elevated glandular projections.^[3] Externally, the nipple-areola complex (NAC) projects outward from the breast skin, with the nipple capable of visible erection in response to stimuli like cold or touch, mediated by contraction of smooth muscle fibers beneath the skin.^[30] This erectile response enhances sensory function and, in females, facilitates milk ejection.^[1] In both sexes, the external NAC lacks significant muscle attachment directly to the overlying skin but is anchored by fibrous bands (suspensory ligaments) extending from the dermis to deeper breast tissue, maintaining its protrusion and position relative to the chest wall.^[3] Sensitivity arises from dense innervation of the nipple skin, particularly Meissner's corpuscles and free nerve endings, making it one of the most tactilely responsive areas on the body surface.^[30] Pathological alterations, such as inversion or retraction, deviate from this protuberant norm and may indicate underlying ductal issues, though most individuals exhibit an everted configuration at rest.^[5]

Internal Components

The internal structure of the nipple comprises a fibroelastic stroma rich in smooth muscle fibers, sensory nerve endings, and the terminal segments of lactiferous ducts, lacking subcutaneous fat.^[1]^[31] These components enable nipple protrusion, milk ejection, and sensory responsiveness.^[1] Beneath the nipple's stratified squamous epithelium lies a thin layer of smooth muscle fibers, termed areolar muscle, oriented in radial (Meyerholz’s muscle), circular (Sappey’s muscle), and longitudinal directions.^[1] These involuntary fibers contract in response to stimuli such as cold, tactile sensation, or sexual arousal, causing nipple erection and aiding the ejection of milk by compressing surrounding ducts.^[31]^[32] The smooth muscle bundles extend from the areola into the nipple, forming outer, intermediate, and inner layers that integrate with dense fibrous connective tissue for structural support.^[1] The lactiferous ducts, numbering 10 to 20 per breast, converge radially toward the nipple, dilating into lactiferous sinuses beneath the areola before narrowing at the nipple base to terminate in small orifices (approximately 0.5 mm in diameter) equipped with sphincters to regulate milk flow and prevent leakage.^[1]^[31] These ducts are lined by a bilayered epithelium—inner luminal cells (cuboidal to columnar) and outer myoepithelial cells—and are enveloped by basement membrane, smooth muscle, and collagenous stroma with elastic fibers, which maintain ductal patency and facilitate peristaltic propulsion during lactation.^[32]^[1] Sensory innervation arises primarily from the fourth intercostal nerve (T4 dermatome), with abundant free nerve endings in the dermis providing erogenous and tactile sensitivity.^[1] A dense lymphatic plexus occupies the deep nipple aspect, draining toward axillary and internal mammary nodes, while vascular supply derives from perforating branches of the internal thoracic artery.^[1] Connective tissue, including collagen and elastic fibers, anchors these elements, ensuring resilience and preventing collapse under mechanical stress.^[32]^[1]

Sex-Specific Differences

Human nipples are homologous structures in both sexes, arising from the same embryonic mammary ridges, but exhibit distinct morphological differences influenced by sex hormones during development. In females, estrogen-driven puberty leads to nipple enlargement and protrusion, correlating with the expansion of underlying mammary tissue, whereas in males, testosterone inhibits such glandular proliferation, resulting in smaller, flatter nipples.^[33] Morphometric studies reveal that female nipples display significantly greater size variability than male nipples, with the latter averaging about 36% of female nipple dimensions across measured samples. Male nipple-areola complexes (NAC) tend to be more oval in shape, positioned more laterally relative to the sternal midline, and located superiorly (higher on the chest wall) compared to female NAC.^[34] Internally, female nipples connect to a network of 15-20 lactiferous ducts draining lobular glandular tissue essential for lactation, whereas male nipples possess rudimentary ducts without functional lobules, rendering the structure vestigial for milk production.^[33]^[35] These differences underscore the nipple's adaptive role in female reproductive physiology while maintaining basic sensory innervation in both sexes.^[1]

Function

Lactation Mechanism

Lactation begins with milk synthesis in the alveolar epithelial cells of the mammary gland lobules, where prolactin from the anterior pituitary stimulates the uptake of nutrients from blood plasma and their conversion into milk components such as lactose, proteins, and lipids.^[36] This process, known as lactogenesis, transitions from secretory activation post-placental delivery to ongoing production maintained by recurrent nipple stimulation from suckling, which inhibits feedback mechanisms downregulating prolactin receptors.^[37] Prolactin levels peak in response to nipple-areola complex stimulation via neural afferents to the hypothalamus, ensuring galactopoiesis aligns with infant demand.^[38] Milk ejection, or the let-down reflex, is triggered by oxytocin release from the posterior pituitary, initiated when mechanoreceptors in the nipple and areola detect suckling pressure and transmit signals via spinal cord pathways to the hypothalamus.^[39] Oxytocin binds to receptors on myoepithelial cells enveloping the alveoli, inducing their contraction and forcing milk into the ductal system against low intraductal pressure.^[40] This reflex can occur multiple times per feeding session, with oxytocin pulses lasting seconds, and is conditioned by auditory or visual maternal cues over time, though primary initiation relies on direct nipple stimulation.^[41] The ductal architecture facilitates milk transport: synthesized milk accumulates in alveoli, drains into intralobular ducts, converges in lactiferous sinuses under the areola for storage, and exits through 4 to 18 lactiferous ducts that traverse the nipple core, opening at its summit via Montgomery's glands-influenced orifices.^[3] Nipple erectile tissue and smooth muscle contract during ejection, widening pores and aiding flow, while the average human nipple contains approximately nine ductal openings, enabling radial milk release during coordinated suckling-compression cycles.^[1] Disruptions in nipple stimulation, such as infrequent feeding, reduce both hormonal surges and milk volume via causal feedback loops prioritizing energy conservation.^[40]

Sensory Functions

The nipple is densely innervated by sensory nerve fibers, primarily from the anterior and lateral cutaneous branches of the second through sixth intercostal nerves, which supply the nipple-areola complex.^[42] Histological analysis of human nipples reveals a rich network of mechanoreceptors and free nerve endings, contributing to its high tactile sensitivity, with nerve fiber density supporting both protective and pleasurable sensations.^[43] This innervation pattern explains the nipple's role as a specialized sensory structure, distinct from surrounding breast tissue, where tactile stimuli are processed as discrete units anchored to the nipple itself.^[44] In sexual contexts, nipple stimulation activates sensory pathways that enhance arousal, with brain imaging showing nipple sensations mapping to the genital sensory cortex, similar to genital stimulation.^[45] Empirical surveys indicate that nipple or breast manipulation induces or augments sexual excitement in approximately 82% of young women and 52% of young men, often eliciting physiological responses like nipple erection as an arousal indicator.^[46] These effects stem from the nipple's concentration of nerve endings—estimated in the hundreds per nipple—triggering oxytocin release and genital vasocongestion, independent of sex.^[47] Sensitivity varies individually, but the nipple ranks among primary erogenous zones due to this neural density, though quantitative comparisons to sites like the clitoris show overlapping but not identical thresholds.^[48] During breastfeeding, nipple sensory input drives the oxytocin reflex: suckling stimulates mechanoreceptors, signaling the hypothalamus to release oxytocin, which contracts myoepithelial cells around milk ducts for ejection (let-down).^[40] This neurogenic pathway operates via afferent nerves from the nipple to the spinal cord and brain, with oxytocin surges occurring even anticipatorily but peaking with tactile contact, facilitating milk flow without conscious effort.^[49] Disruption of nipple sensation, as in nerve damage, can impair this reflex, underscoring its causal role in lactation efficiency over prolactin-mediated milk production alone.^[50] In males, analogous sensory mechanisms exist but lack the lactational endpoint, focusing instead on reflexive or affiliative responses.^[51]

Evolutionary Biology

Ancestral Origins

The nipple represents a derived feature in the evolution of therian mammals (marsupials and placentals), emerging as a specialized elevation of the mammary areola that centralizes milk ducts for efficient suckling.^[52] In contrast, the ancestral mammary apparatus in earlier synapsids and monotreme mammals lacked true nipples, relying instead on diffuse areolar patches where milk seeped from multiple pores associated with hair follicles.^[53] These patches derive from apocrine-like cutaneous glands that likely functioned initially to provide moisture, antimicrobial secretions, or nourishment to eggs or hatchlings in proto-mammalian reptiles dating back to the Permian period, approximately 310 million years ago.^[54] ^[55] Comparative anatomy indicates that nipples proper arose after the divergence of monotremes from other mammals around 166–180 million years ago in the Jurassic, coinciding with the therian lineage's adaptations for viviparity and active nursing.^[52] This innovation rendered ancestral "mammary hairs"—specialized follicles that may have aided milk distribution in non-nippled forms—obsolete, as the nipple's teat structure concentrated glandular outputs into a single conduit, enhancing infant attachment and milk transfer efficiency.^[53] Fossil evidence for soft-tissue mammary structures is absent due to poor preservation, but indirect support comes from synapsid cranial features implying extended parental care and delayed tooth eruption, consistent with lactation demands predating nipples by tens of millions of years.^[56] ^[57] The transition to nipples likely imposed selective pressures favoring fewer but larger glands per litter, as evidenced by correlations between nipple count and fecundity in extant mammals, suggesting an ancestral constraint where nipple evolution facilitated scalable reproductive strategies in increasingly complex mammalian lineages.^[58] This development underscores a causal shift from passive seepage to active maternal-infant interaction, aligning with broader synapsid trends toward endothermy and hair-bearing skin.^[59]

Development of Sex Differences

In human embryogenesis, the mammary ridges, precursors to the nipples and breasts, first appear bilaterally along the ventral body wall around days 35 to 38 of gestation, prior to gonadal sex differentiation.^[14] Nipple primordia emerge as epidermal thickenings from these ridges between weeks 4 and 7, forming rudimentary buds that canalize into lactiferous ducts in both male and female fetuses; at this stage, no morphological sex differences are evident in nipple or mammary bud formation.^[14] ^[60] Gonadal differentiation begins around week 6 to 7, with the testes producing anti-Müllerian hormone (AMH) and testosterone, which initiate male-specific pathways but do not eliminate the pre-formed nipple structures.^[61] In male fetuses, androgens promote mesenchymal differentiation around the mammary epithelium, leading to partial regression of glandular components via immune cell infiltration (analogous to macrophage-mediated removal observed in murine models), resulting in rudimentary ductal structures that remain underdeveloped compared to females.^[62] ^[61] Female fetuses, lacking these androgens, exhibit continued but minimal prenatal mammary bud progression, with nipples typically protruding slightly by birth in both sexes due to mesenchymal proliferation.^[14] Postnatally, transient surges of maternal hormones can cause temporary nipple enlargement or "witch's milk" secretion in both male and female newborns, resolving within weeks without sex-based divergence.^[14] True sex differences in nipple morphology—such as larger size, greater pigmentation, and erectile tissue development in females—emerge primarily at puberty under estrogen influence, which expands the areola, elongates ducts, and enhances nipple projection, while male nipples remain smaller and less responsive due to androgen dominance inhibiting further glandular and stromal growth.^[63] ^[14] This dimorphism underscores the nipple's conserved embryonic origin, with male persistence reflecting incomplete suppression rather than adaptive equivalence.^[64]

Adaptive Variations

In mammals, the number of nipples exhibits adaptive variation correlated with typical litter size, enabling efficient parallel nursing of multiple offspring and thereby enhancing juvenile survival rates in species with higher fecundity. For instance, monotocous primates like humans possess two nipples, sufficient for usually singleton or twin births, whereas polytocous species such as pigs have 10 to 14, allowing simultaneous feeding that reduces competition and starvation risk among littermates.^[58] This linkage suggests that mammary gland count imposes an evolutionary constraint on litter size expansion, with fewer nipples potentially limiting reproductive output in low-mammae lineages.^[58] Human nipples display sexually dimorphic variation in size and shape, with females exhibiting greater diversity in nipple length, width, and protrusion compared to the more uniform morphology in males. This pattern deviates from traditional evolutionary expectations of heightened variance in the sex facing stronger sexual selection—typically males—but aligns with lactation demands driving diversification in females to optimize infant latching and milk ejection efficiency across diverse neonatal mouth sizes and suckling strengths.^[65] Male nipples, vestigial for lactation yet retaining sensory innervation, represent a developmental spandrel arising from shared embryonic pathways predating gonadal differentiation around week 7 of gestation, where nipple primordia form prior to sex-specific hormone influences.^[2] Across mammals, nipple hairlessness constitutes an adaptation for unobstructed suckling, contrasting with haired teats in some species and facilitating targeted milk delivery with minimal infant effort, particularly advantageous in altricial young requiring precise areolar contact.^[66] In humans, this trait, combined with erectile areolar tissue responsive to tactile and thermal stimuli, supports both nutritive and potential affiliative functions, though empirical evidence for non-lactational adaptations remains limited to correlative sensory roles rather than direct selective pressures.^[2]

Variations and Disorders

Normal Variations

Nipples exhibit natural variations in shape, including everted (protruding), flat, and inverted forms. Inverted nipples, characterized by retraction into the breast rather than outward projection, arise congenitally from short lactiferous ducts or a constricted areolar muscle sphincter and occur in both sexes.^[1] ^[11] This inversion represents a benign developmental variant rather than pathology unless associated with recent onset or unilateral change, which may warrant evaluation for underlying conditions.^[5] Flat nipples, which neither protrude nor retract significantly, also fall within normal morphology and may respond to stimulation by temporary eversion.^[26] Size variations include differences in diameter and projection, with adult nipple diameters typically measuring 10-20 mm, though precise ranges depend on sex, parity, and hormonal influences. In non-lactating women, average diameters approximate 12-15 mm, while lactating individuals show slight enlargement to around 15-16 mm bilaterally.^[67] Male nipples tend toward smaller dimensions and reduced prominence compared to females, reflecting lower estrogen exposure during development. Asymmetry in nipple height, diameter, or projection between bilateral structures occurs frequently and constitutes a normal anthropometric feature, with deviations of up to several millimeters common in healthy populations.^[68] Supernumerary nipples (polythelia), extra nipple structures along the embryonic mammary ridge from axilla to groin, occur in 0.2-5% of humans as a vestigial trait without functional glandular tissue in most cases. Prevalence varies geographically, reported at 0.22% in European cohorts and up to 1.63% in African American groups, underscoring polythelia's benign, atavistic nature rather than anomaly requiring intervention.^[14] ^[69] These often manifest as small, pigmented papules mistaken for nevi and rarely develop lactational capability. Areolar features, including the number and prominence of Montgomery's tubercles (sebaceous glands), vary individually and increase during pregnancy as a normal adaptive response. Pigmentation gradients from nipple to areola differ by genetic factors, with darker tones in individuals of African or South Asian descent reflecting melanin distribution patterns inherent to skin phototype.^[11] Such variations maintain physiological integrity, supporting thermoregulation, sensation, and potential lactation without clinical impairment.

Pathological Conditions

Pathological conditions affecting the nipple include inflammatory, infectious, neoplastic, and ductal disorders that can cause pain, discharge, ulceration, or structural changes, often requiring clinical evaluation to distinguish from benign variations. These conditions may arise from obstruction, infection, or malignant transformation within the lactiferous ducts or overlying skin, with symptoms frequently overlapping across etiologies. Diagnosis typically involves physical examination, imaging such as mammography or ductography, and biopsy, as many presentations mimic dermatitis or trauma.^[70]^[71] Inflammatory and infectious pathologies commonly manifest as erythema, edema, or erosion of the nipple-areola complex. Eczema or contact dermatitis presents with pruritus, scaling, and fissuring, often triggered by irritants or allergens, and affects up to 10% of breastfeeding individuals due to moisture and friction.^[72] Subareolar abscesses, also known as Zuska's disease or periductal mastitis, result from squamous metaplasia of lactiferous ducts leading to keratin debris obstruction, bacterial superinfection (typically Staphylococcus aureus), and recurrent inflammation; incidence peaks in women aged 30-50, with fistulas forming in 20-30% of untreated cases.^[73] Abscesses of Montgomery tubercles, the sebaceous glands surrounding the areola, arise from blocked ducts and present as localized tender nodules with purulent discharge.^[70] Fungal infections like candidal intertrigo occur in moist environments, such as during lactation, causing satellite lesions and white plaques responsive to antifungals.^[74] Neoplastic conditions range from benign adenomas to malignancies, with the latter often involving ductal carcinoma extension. Paget's disease of the nipple, a rare adenocarcinoma comprising 1-4% of breast cancers, features eczematous changes—redness, scaling, and nipple inversion—due to intraepidermal spread of malignant cells from underlying ductal carcinoma in situ (DCIS) or invasive carcinoma in over 90% of cases; it predominantly affects women over 50, with a five-year survival rate of 76-96% when underlying lesions are addressed via mastectomy or lumpectomy.^[75]^[76] Nipple adenomas, benign glandular proliferations, cause erosion or discharge in middle-aged women and histologically resemble tubular carcinoma, necessitating excision to rule out atypia.^[77] Intraductal papillomas, the most frequent cause of pathologic bloody discharge (35-58% of cases), are solitary or multiple fibrovascular growths within ducts that may harbor atypical cells, warranting microdochectomy for diagnosis.^[78] Pathologic nipple discharge, defined as spontaneous, unilateral, or serosanguinous from a single duct, signals underlying ductal pathology in 10-15% of non-lactational cases, contrasting physiologic bilateral galactorrhea from prolactin excess. Common etiologies include mammary duct ectasia (dilated ducts with inspissated secretions, causing sticky multicolored discharge in perimenopausal women) and, less frequently, endocrine disorders like hyperprolactinemia from pituitary adenomas or medications.^[79]^[80] Malignancy accounts for 5-20% of such discharges, emphasizing cytologic evaluation and duct excision.^[81] Congenital anomalies qualify as pathological when functionally impairing or syndromically linked, such as polythelia (supernumerary nipples along the embryonic milk line, occurring in 0.2-5.6% of individuals) potentially associating with renal malformations in 10-20% of cases per some studies, though causality remains unproven and screening is not universally recommended.^[69] Athelia (congenital nipple absence) is rarer, often part of Poland syndrome or ectodermal dysplasias, leading to absent lactation and requiring reconstructive surgery if symptomatic.^[82] Acquired inversion from fibrosis or malignancy further compromises breastfeeding and hygiene.^[83]

Clinical Aspects

Diagnostic Indicators

Diagnostic indicators for nipple abnormalities primarily involve clinical examination, focusing on visual inspection, palpation, and assessment of discharge to differentiate normal variations from pathological changes.^[84] Normal nipples exhibit protrusion, flatness, or congenital inversion without recent change, symmetric appearance, and smooth skin texture; deviations such as acquired inversion, retraction, or asymmetry suggest underlying pathology like ductal carcinoma or fibrosis.^[85] ^[84] Skin alterations serve as key visual cues, including erythema, scaling, crusting, erosion, or ulceration, which may indicate inflammatory conditions or malignancy such as Paget's disease of the nipple, characterized by eczematous changes progressing to nipple flattening or bloody discharge in approximately 50% of cases associated with underlying invasive breast cancer.^[86] ^[87] Acquired swelling or edema of the nipple-areola complex can signal benign processes like infection or malignant infiltration, warranting further imaging.^[71] Nipple discharge evaluation classifies it as physiologic (bilateral, multiductal, non-spontaneous, milky or clear) versus pathologic (unilateral, single-duct, spontaneous, serous, bloody, or serosanguinous), with the latter prompting investigation for intraductal papilloma, duct ectasia, or carcinoma; bloody discharge, in particular, correlates with malignancy in up to 15-20% of cases.^[74] ^[88] Palpation assesses for tenderness, induration, or subareolar masses, while bilateral symmetry in vascularity on Doppler ultrasound aids in distinguishing benign from hypervascular pathological states, though clinical findings guide initial triage before advanced modalities like mammography or sonography.^[89] ^[90]

Pain and Discharge

Nipple pain, also known as mastodynia when involving the breast, commonly arises from benign causes such as friction from ill-fitting clothing or repetitive motion during exercise, which irritates the sensitive skin and underlying tissue.^[91] Hormonal fluctuations, particularly during the menstrual cycle, pregnancy, or menopause, can lead to cyclic tenderness due to estrogen and progesterone variations affecting breast tissue sensitivity.^[92] In lactating individuals, improper latch during breastfeeding frequently causes soreness, often described as sharp or burning, resolving with technique adjustments.^[93] Dermatological conditions like eczema, psoriasis, or contact dermatitis from soaps, detergents, or allergens may present as itchy, painful inflammation around the nipple-areola complex.^[94] Infections such as mastitis or candidiasis can produce acute pain, often accompanied by redness, swelling, and fever, particularly in breastfeeding or perimenopausal women.^[95] Less commonly, nipple pain signals underlying pathology; for instance, Paget's disease of the breast, a rare form of ductal carcinoma in situ, manifests with persistent unilateral pain, itching, and eczematous changes, affecting approximately 1-4% of breast cancer cases.^[94] In males, gynecomastia or referred pain from cardiac or gastrointestinal issues may contribute, though friction and dermatitis remain primary etiologies.^[96] Evaluation typically involves history, physical exam, and imaging if persistent or unilateral, as most cases resolve with conservative measures like moisturizers, supportive bras, or topical steroids.^[97] Nipple discharge occurs in up to 50% of non-pregnant women at some point, often physiologic and bilateral from hormonal influences like prolactin elevation due to stress, medications (e.g., antipsychotics), or hypothyroidism.^[98] Pathologic discharge—spontaneous, unilateral, or serous/bloody—warrants investigation; intraductal papilloma, a benign tumor in 35-56% of cases, commonly causes watery or bloody discharge from a single duct.^[81] Duct ectasia, prevalent in perimenopausal women, leads to thick, multicolored discharge from ductal dilation and inflammation, affecting 6-59% of pathologic cases.^[99] Infections like periductal mastitis produce purulent discharge with pain, while mammary duct ectasia may mimic this without infection. Malignancy accounts for 10-15% of pathologic discharges, primarily ductal carcinoma in situ or invasive ductal carcinoma, with bloody discharge raising suspicion, especially in women over 50 or with palpable masses.^[74] Paget's disease may combine discharge with pain and nipple inversion.^[100] Diagnosis involves cytologic analysis, mammography, ductography, or MRI; prolactin levels and endocrine evaluation rule out pituitary adenomas causing galactorrhea.^[101] Treatment targets etiology: excision for papillomas, antibiotics for infections, or surgery/hormonal therapy for neoplasms.^[102] Persistent symptoms necessitate referral to exclude carcinoma, though benign causes predominate.^[103]

Neoplastic Risks

Paget's disease of the nipple represents a rare malignant neoplasm, comprising approximately 1% of all breast cancers, characterized by intraepidermal adenocarcinoma cells originating from underlying ductal carcinoma in most cases.^[104] It typically presents with eczematous changes, erythema, scaling, or ulceration confined to the nipple-areola complex, often delaying diagnosis due to mimicry of benign dermatoses.^[76] In about 90% of instances, it coexists with invasive or in situ breast carcinoma beneath the nipple, with roughly half of patients exhibiting a palpable underlying lump at diagnosis.^[86] Risk factors include age over 50 years and family history of breast cancer, though it remains infrequent overall, affecting women predominantly but reported rarely in men.^[105] Nipple-areola complex involvement occurs in 5-20% of invasive breast carcinomas, usually via direct tumor extension from retroareolar ducts rather than primary nipple origin, with higher rates in centrally located or multifocal tumors.^[106] ^[107] Primary invasive carcinomas arising de novo in the nipple are exceptionally rare, presenting as subtle thickening or crusting and necessitating histologic confirmation to distinguish from extension of parenchymal disease.^[108] Tumor-to-nipple distance on mammography serves as a predictor of such involvement, with closer proximity correlating to increased risk, informing decisions in nipple-sparing mastectomy where occult invasion can reach 10-20% despite clinical absence of symptoms.^[109] ^[110] Benign neoplasms of the nipple, such as nipple adenomas, manifest as localized epithelial proliferations in large ducts, often resembling sclerosing adenosis or papillomatosis and potentially mimicking invasive carcinoma clinically or radiologically due to firmness or erosion.^[111] These lesions are uncommon, typically unilateral, and harbor low malignant potential, though complete excision is advised to rule out atypia or associated ductal carcinoma in situ.^[73] Rarer benign entities include leiomyomas, neurofibromas, and florid papillomatosis, which may cause discharge or inversion but generally follow a non-progressive course without oncogenic transformation.^[112]

Surgical and Reconstructive Procedures

Nipple-sparing mastectomy (NSM) preserves the nipple-areola complex (NAC) during breast cancer surgery, allowing for immediate or delayed reconstruction while minimizing aesthetic disruption. Incisions placed away from the NAC reduce ischemic complications, with necrosis rates reported at approximately 6.4% in systematic reviews of long-term outcomes. Oncologic safety is supported by low NAC recurrence rates, such as 0.18% in large cohorts undergoing NSM with immediate reconstruction, comparable to skin-sparing techniques. Patient satisfaction is higher with NSM due to retained natural contours, though risks include skin necrosis up to 8% and potential need for reoperation.^[113]^[114]^[115] Nipple reconstruction following mastectomy typically occurs 4-6 months post-procedure using local flaps to achieve projection and symmetry. Common techniques include the C-V flap, which provides reliable projection with long-term stability in projection and sensation preservation, and the skate flap or V-Y advancement for incorporating prior scars in wise-pattern mastectomies. These methods exhibit low operative morbidity and high reproducibility, with patient-reported enhancements in body image confidence. The five-flap technique combines multiple local flaps for NAC reconstruction, emphasizing minimal donor site distortion.^[116]^[117]^[118] Surgical correction of inverted nipples addresses tethering by shortened milk ducts or fibrotic bands, classified by severity from grade 1 (easily everted) to grade 3 (fixed inversion). For moderate to severe cases, procedures involve small incisions at the base to release ducts and reshape tissue, such as the double triangle suture technique, which uses minimal sutures and incisions for reliable eversion with low recurrence. More invasive methods for grade 3 may sacrifice ductal integrity, potentially impairing lactation, though sensation is often preserved. These outpatient procedures under local anesthesia yield high satisfaction but require careful patient selection to balance aesthetics and function.^[119]^[120] Nipple reduction surgery targets hypertrophy or protrusion, indicated for asymmetry, disproportion relative to breast size, or functional discomfort. Techniques encompass wedge resection of the inferior nipple base, circumcision excision, or flap-based methods to maintain vascularity and sensation, with patient satisfaction rates exceeding 90% in reviews of five primary approaches. Performed via small periareolar incisions, these procedures minimize scarring while preserving erectile function.^[121] In gynecomastia correction, nipple procedures often involve glandular excision through periareolar incisions, with repositioning or areola reduction to achieve masculine contours. For puffy or herniated nipples, direct excision or dermoglandular flap techniques reposition the NAC, reducing prominence while avoiding over-resection that could impair sensation. These steps integrate with liposuction or skin excision, prioritizing minimal scarring in male patients.^[122]^[123]

Society and Culture

Norms of Exposure

In contemporary Western societies, exposure of male nipples is generally accepted in public settings such as beaches, sports, or casual attire, reflecting norms that do not associate male torsos with sexual provocation.^[124] In contrast, female nipple exposure is widely regarded as indecent, often prohibited under laws against public nudity or lewdness, with statutes targeting the areola and nipple specifically to maintain public order and morality.^[125] ^[126] For instance, in Arizona as of 2014, a woman risks arrest for exposing her areola or nipple in the presence of others, underscoring a gendered distinction rooted in perceptions of female breasts as inherently erotic.^[127] Legally, female toplessness remains restricted in most U.S. states and many European countries, though enforcement varies; courts have upheld such ordinances as constitutional for protecting societal sensibilities rather than violating free speech, absent evidence of expressive intent.^[128] In the European Union, norms differ by nation—toplessness is permitted on many beaches in France and Spain but banned in public streets elsewhere—while Instagram and similar platforms enforce global content policies censoring female nipples as obscene, a rule not applied to males.^[129] These disparities persist despite challenges from movements like Free the Nipple, launched in 2012, which advocate for legal parity but have achieved limited policy changes, such as relaxed beach rules in select U.S. localities, without altering core indecent exposure statutes.^[130] ^[131] Historically, Western norms shifted toward concealment around the 18th-century Enlightenment, when topless depictions in art gave way to Victorian-era prudery emphasizing female modesty; prior Greco-Roman precedents featured breast exposure in fertility symbols or athletic contexts, yet even then, full public toplessness among women was not routine.^[132] ^[133] Public breastfeeding, involving transient nipple exposure, is legally protected in 49 U.S. states and many nations under health policies promoting infant nutrition, but social expectations often demand discretion via covers or private spaces to avoid discomfort, reflecting lingering taboos.^[134] ^[135] Cross-culturally, norms diverge sharply; among the Himba people of Namibia, women traditionally forgo upper garments, exposing breasts as a non-sexual norm tied to practicality in hot climates and cultural identity, without the erotic connotations prevalent in industrialized societies.^[133] In Papua New Guinea highland groups, studies indicate that habitual female toplessness does not eliminate male arousal responses to breasts, suggesting evolutionary bases for sexualization that transcend cultural habituation.^[136] Such variations highlight how exposure norms arise from environmental, utilitarian, and symbolic factors rather than universal taboos, though globalization increasingly imposes Western modesty standards on indigenous practices.^[137]

Sexual and Symbolic Roles

Nipples function as erogenous zones, with stimulation triggering physiological responses that contribute to sexual arousal in both sexes. Manipulation of the nipples or breasts enhances or induces sexual arousal in about 82% of young women and 52% of young men, according to a 2006 survey-based study involving 371 participants aged 17-29.^[46] This arousal stems from dense nerve endings in the nipple-areola complex, which transmit signals to the genital sensory cortex, mirroring activation patterns from clitoral or penile stimulation.^[138] In females, nipple stimulation during intercourse correlates with increased physical pleasure and emotional bonding, potentially via oxytocin release, as evidenced by self-reported data from sexual response analyses.^[139] For males, nipple erection evokes similar emotional responses to female nipple erection, including perceptions of sexual interest, per a 2022 experimental study.^[140] Intense or prolonged nipple stimulation can culminate in orgasm independent of genital contact, termed nipple orgasm, due to converging neural pathways that amplify sensory feedback. Peer-reviewed accounts confirm this phenomenon's feasibility, with hundreds of nerve endings enabling heightened sensitivity akin to other erogenous areas.^[47] Such responses underscore nipples' role in sexual physiology beyond reproduction, rooted in evolutionary adaptations for pair-bonding and pleasure rather than solely lactation cues. However, individual variability exists, with 7-8% of respondents in arousal studies reporting decreased excitement from stimulation.^[46] Symbolically, nipples have represented fertility, nourishment, and social status across cultures, often decoupled from explicit sexuality. In ancient Greek philosophy, some thinkers advocated female toplessness to affirm equality, viewing breasts as non-private and non-sexual attributes.^[133] European Renaissance and Baroque art frequently depicted exposed female nipples to signify virtue, maternal abundance, or aristocratic lineage, as in 18th-century portraits where one bared breast connoted moral integrity without erotic intent.^[141]^[142] For example, François-Hubert Drouais's 1776 portrait of the Princess of Lamballe features a semi-exposed breast to evoke classical ideals of purity and nobility. In non-Western contexts, such as certain African tribal traditions, pendulous breasts symbolized life-sustaining capacity over sexual appeal, prioritizing communal roles in sustenance.^[133] These depictions highlight causal links between nipple visibility and cultural signaling of status or vitality, predating modern Western sexualization influenced by 19th-century modesty norms.^[143]

Body Modifications

Nipple piercings involve perforating the base of the nipple to insert jewelry such as barbells or rings, a practice associated with body adornment, sexual enhancement, and cultural symbolism.^[144] The horizontal piercing, using a straight or curved barbell, is the most common type due to the nipple's anatomy, though vertical and surface options exist.^[145] Materials typically include surgical steel, titanium, or gold to minimize allergic reactions.^[146] Historically, reliable documentation of nipple piercings is limited, with many ancient claims—such as Roman soldiers wearing them for strength—originating from unverified 20th-century accounts rather than primary sources.^[145] In the 19th century, piercings appeared in Victorian England among some women for aesthetic enhancement, often linked to corset aesthetics, though evidence remains anecdotal.^[147] Modern popularity surged in the late 20th century within body modification subcultures, influenced by punk and BDSM communities, evolving into mainstream fashion by the 2010s.^[148] Complications from nipple piercings include bacterial infections, abscess formation, and delayed healing, with risks heightened by poor hygiene or non-sterile procedures.^[144] Localized cellulitis occurs frequently, treatable with antibiotics, while rare cases involve endocarditis or mastitis.^[149] Piercings may interfere with breastfeeding by causing infant discomfort or inhibiting milk letdown, though most women lactate successfully post-removal.^[150] One case report linked a piercing site to invasive ductal carcinoma, but causation remains unestablished beyond potential chronic irritation.^[151] Nipple tattoos represent another modification, particularly in medical reconstruction following mastectomy, where 3D areola pigmentation simulates natural appearance without surgery.^[152] Performed 3-6 months post-reconstruction, these use layered pigments for depth and realism, offering lower risk than surgical nipple grafts.^[153] In non-medical contexts, decorative nipple tattoos enhance aesthetics but carry standard tattoo risks like infection or fading.^[154] Culturally, such modifications signify resilience in breast cancer survivors, with tattooing alone sufficient for some irradiated tissues unfit for surgery.^[155]

Debates and Controversies

The "Free the Nipple" campaign, initiated in 2012 during pre-production of a related film, advocates for the legalization of female toplessness in public spaces equivalent to male toplessness, arguing that existing indecency laws enforce a discriminatory double standard based on sex.^[156] Proponents claim this disparity stems from cultural taboos associating female nipples with sexuality, despite their biological homology to male nipples and primary function in lactation.^[157] Critics contend the movement overlooks evolutionary and social realities, where female breasts serve as secondary sexual signals eliciting arousal, justifying distinct norms to maintain public decorum without implying moral inferiority.^[158] In the United States, female public toplessness remains legally restricted in most jurisdictions under state indecency statutes, though interpretations vary; for instance, the Minnesota Supreme Court ruled on May 5, 2025, that nonsexual female toplessness does not constitute lewdness, overturning prior convictions.^[159] Federal courts have rejected blanket First Amendment protections for toplessness, viewing it as non-expressive conduct rather than speech, while equal protection challenges under the Fourteenth Amendment have succeeded in some circuits by deeming sex-specific bans irrational absent evidence of unique harms from female exposure.^[128] No nationwide uniformity exists, with at least six states permitting it post-federal rulings as of January 2025, but enforcement often hinges on context, leading to arrests for perceived intent to provoke.^[160] Social media platforms exacerbate the debate through policies prohibiting images of female nipples while permitting male ones, a rule enforced by Meta (Facebook and Instagram) since at least 2015, resulting in removals of artistic, educational, and breastfeeding content.^[124] This "nipocrisy" has prompted challenges, including the 2017 Genderless Nipples account, which amassed 50,000 followers by posting ambiguous close-ups to highlight identifiability issues, and the 2019 We The Nipple campaign urging policy revisions for artistic nudity.^[161]^[162] Platforms defend the distinction citing community standards against sexual content, but data indicate female-presenting bodies are flagged twice as often, raising concerns over algorithmic bias and disproportionate impact on women artists and survivors sharing mastectomy images.^[163] Public breastfeeding, involving incidental nipple exposure, sparks recurrent controversies despite legal protections in all 50 U.S. states allowing it in any public or private location where mothers are permitted.^[164] Incidents include mothers being asked to cover up or relocate in restaurants, malls, and flights, as in a 2019 USA Today-reported wave of confrontations, fostering embarrassment and reduced breastfeeding rates due to perceived social stigma.^[165] Advocates argue such demands ignore the act's natural, non-sexual purpose, supported by empirical evidence of breastfeeding's health benefits for infants, including reduced infection risks; opponents, however, cite discomfort from unintended exposure in mixed settings, prompting calls for discretion without legal compulsion.^[166] In artistic contexts, nipple censorship persists, with platforms removing historical works like Renaissance paintings or modern exhibits, as seen in a July 2024 Florida city hall reversal after censoring a cancer survivor's nipple-inclusive portrait.^[167] Meta's oversight board critiqued the female nipple ban in April 2023 as potentially discriminatory, yet upheld it with narrow exceptions for activism or health education, fueling ongoing advocacy from groups like the National Coalition Against Censorship for broader exemptions to preserve expressive freedom.^[168]^[162] This policy traces to Victorian-era moral codes equating female nipple visibility with indecency, contrasting male norms and limiting discourse on body positivity and medical realities.^[169]

References

[1]
Anatomy of the nipple and breast ducts - PMC - PubMed Central - NIH
Its skin is similar to the areola, but has no sebaceous glands. It has 10 to 20 corresponding pores as the output of the milk ducts. The NAC has no subcutaneous ...
[2]
Why do men have nipples? - Scientific American
The presence of nipples in male mammals is a genetic architectural by-product of nipples in females. So, why do men have nipples? Because females do.Missing: empirical | Show results with:empirical
[3]
Anatomy, Thorax: Mammary Gland - StatPearls - NCBI Bookshelf
The mammary gland is a highly evolved and specialized organ developing on each side of the anterior chest wall. This organ's primary function is to secrete milk ...
[4]
The nipple: a simple intersection of mammary gland and integument ...
We provide a brief overview of the development and anatomy of nipples and mammary glands in monotremes, marsupials, and marine mammals.Missing: empirical | Show results with:empirical
[5]
Inverted Nipple - StatPearls - NCBI Bookshelf - NIH
An inverted nipple is a condition defined as the nipple, which is retracted inwards, rather than pointing outwards, as is seen in normal anatomy.
[6]
Nipple - Etymology, Origin & Meaning
Originating in the 1530s as a diminutive of neb ("bill, beak"), nipple means a small projection, originally the mammary protuberance where milk discharges.
[7]
https://www.merriam-webster.com/dictionary/nipple
[8]
Papilla - Etymology, Origin & Meaning
Originating from Latin papilla, meaning "nipple," this word first meant a mammary gland nipple (1690s) and later a nipple-like protuberance (1713).
[9]
NIPPLE Definition & Meaning | Dictionary.com
Word History and Origins. Origin of nipple. 1520–30; earlier neble, nib ( b ) ... Word History and Origins. Origin of nipple. C16: from earlier neble ...
[10]
The nipple-areolar complex: anatomy, methods and pathologic ...
The nipple-areolar complex is a specialized region of the mammary gland. It is a major anatomic landmark of the breast.
[11]
Anatomy, Thorax, Breast - StatPearls - NCBI Bookshelf - NIH
The condition is also associated with an underdeveloped breast. Amastia is known as the complete absence of all breast tissue except for the nipple areolar ...
[12]
Nipple - an overview | ScienceDirect Topics
The nipple is defined as a round, raised area of modified skin that features 12–20 small openings of large nipple ducts and shows increased melanin ...
[13]
mamilla, n. meanings, etymology and more - Oxford English Dictionary
1. 1684– Anatomy. Originally: †a breast; (later) spec. the male breast (obsolete). Now: the nipple of the breast.
[14]
Development of the Human Breast - PMC - PubMed Central - NIH
Soon after birth, the nipples become everted from proliferation of the underlying mesoderm, and the areolae increase in pigmentation. Development of erectile ...
[15]
Mammary Gland Development - PMC - PubMed Central
The mammary gland develops through several distinct stages. The first transpires in the embryo as the ectoderm forms a mammary line that resolves into placodes.Mammary Gland Development · Embryonic Mammary Gland... · Pubertal Mammary Gland...
[16]
Neonatal Mastauxe (Breast Enlargement of the Newborn) - PMC - NIH
Jul 1, 2013 · Maternal estrogen is known to cause varying degree of breast enlargement in approximately 70% of newborn. [1] Usually the diameter of breast ...
[17]
Hormonal effects in newborns: MedlinePlus Medical Encyclopedia
Jan 1, 2025 · Hormones from the mother may also cause some fluid to leak from the infant's nipples. This is called witch's milk. It is common and most often ...
[18]
Breast Symptoms-Child - Seattle Children's
The nipple area is always firm. Cause: the passage of the mother's hormones across the placenta. Newborn milk: sometimes, the nipples leak a few drops of ...Missing: maternal | Show results with:maternal
[19]
Normal Breast Development and Changes | Johns Hopkins Medicine
Breast development happens in certain stages during a woman's life: first before birth, again at puberty, and later during the childbearing years.
[20]
Normal Breast Development and Changes
What breast changes happen at puberty? ; Buds appear, and breast and nipple are raised. The dark area of skin around the nipple (the areola) gets larger.
[21]
Tanner Stages - StatPearls - NCBI Bookshelf - NIH
Puberty in females begins with the development of breast buds under the areola, also known as thelarche, and represents entry into Tanner Stage 2. As puberty ...
[22]
Anatomy and Physiology of the Breast during Pregnancy and Lactation
The incomplete breast consists mostly of adipose tissue but also lactiferous units called lobes. These eventually drain into the lactiferous ducts and then into ...
[23]
Breast changes during pregnancy: Pictures and symptoms
Nipple and breast changes are not indicative of a person's ability to produce milk or chestfeed.First trimester · Second trimester · Milk production · Easing discomfort
[24]
Breast changes during or after pregnancy
In the last few weeks of pregnancy, the nipples become larger and the breasts continue to grow as the milk-producing cells get bigger. Your breasts may feel ...How breasts change during... · Possible breast problems after...
[25]
Aging changes in the breast: MedlinePlus Medical Encyclopedia
Jul 15, 2024 · The area surrounding the nipple (the areola) becomes smaller and may nearly disappear. The nipple may also turn in slightly. Breast lumps are ...
[26]
Inverted & Flat Nipples: Causes & Treatment - Cleveland Clinic
Age-related breast changes. Your breasts change as you age. Leading up to menopause, your milk ducts may shorten, causing your nipples to invert or lay flat.
[27]
A Study Using Prone Breast Magnetic Resonance Imaging - PubMed
Conclusions: A caudal deviation of the nipple and an increase in volume were age-related changes in breast shape. These 2 variables were also correlated.
[28]
Are Wrinkled Nipples Ever a Cause for Concern? What to Know
Jul 22, 2021 · Nipples are also commonly affected by aging, and may shrink or turn in over time, causing a wrinkled appearance. Inverted nipples. Nipples come ...
[29]
Age-Related Breast Changes: What You Should Know - WebMD
Feb 20, 2024 · Changes to your breasts are a normal part of aging. Changes in firmness or size are very common, especially after menopause.
[30]
Mammary Glands - SEER Training Modules
Functionally, the mammary glands produce milk; structurally, they are modified sweat glands. Mammary glands, which are located in the breast overlying the ...
[31]
Histology, Mammary Glands - StatPearls - NCBI Bookshelf - NIH
May 1, 2023 · Deep to both areola and the nipple, smooth muscle bundle fibers are responsible for nipple erection secondary to various sensory stimuli ...
[32]
Histology - Breast - Pathology Outlines
Apr 17, 2025 · Histology · Consists of large lactiferous ducts that open to the surface of the nipple via lactiferous sinuses, which branch into ducts and ...
[33]
Overview of the Breast - Johns Hopkins Pathology
Anatomy & Physiology of the Breast. The breast is an organ whose structure reflects its special function: the production of milk for lactation (breast feeding).
[34]
A Comparison of Relative Parameters in Male and Female Nipple ...
The results from our study suggest that the male NAC is more oval in shape, more laterally placed, and located more superiorly than the female NAC.Missing: size structure peer- reviewed
[35]
Anatomy of the Gynecomastia Tissue and Its Clinical Significance
Unlike the female breast, male glandular tissue contains no lobules. Gynecomastia is the benign enlargement of this glandular tissue. The histologic ...
[36]
Lactation (Breast Milk Production): How it Works - Cleveland Clinic
Prolactin causes the alveoli to make milk and oxytocin causes muscle contractions that push out of the alveoli and through the milk ducts.
[37]
Physiology, Lactation - StatPearls - NCBI Bookshelf
Lactation is maintained by regular removal of milk and stimulation of the nipple, which triggers prolactin release from the anterior pituitary gland and ...
[38]
Human Milk and Lactation - Medscape Reference
Jun 29, 2021 · The binding of prolactin to receptors on the epithelial cells in the mammary gland stimulates milk production. These receptors are downregulated ...
[39]
Let-down reflex | Pregnancy Birth and Baby
When your baby sucks at your breast, tiny nerves are stimulated. This causes the hypothalamus and pituitary glands in the brain to release 2 hormones into your ...
[40]
The physiological basis of breastfeeding - Infant and Young ... - NCBI
Oxytocin is produced more quickly than prolactin. It makes the milk that is already in the breast flow for the current feed, and helps the baby to get the milk ...
[41]
Dysphoric Milk Ejection Reflex: The Psychoneurobiology of the ... - NIH
Oct 29, 2021 · Oxytocin triggers the let down reflex or the release of milk when the nipple areola is stimulated (23). Although prolactin and oxytocin are ...
[42]
Innervation of the Female Breast and Nipple: A Systematic ... - PubMed
Aug 1, 2022 · The breast skin is innervated by anterior cutaneous branches and lateral cutaneous branches of the second through sixth and the nipple/nipple-areola complex.
[43]
The sensory innervation of the human nipple - PubMed
The histological studies regarding this region are scarce, so 42 human nipples were studied to describe the morphology of the nipple innervation.
[44]
The coarse mental map of the breast is anchored on the nipple - eLife
Apr 8, 2025 · This paper establishes common methods for studying breast tactile sensation and presents the breast and nipple as two fundamentally discrete tactile units from ...
[45]
Nipples 'Light Up' Brain the Way Genitals Do - NBC News
Aug 5, 2011 · A new study may explain why: The sensation from the nipples travels to the same part of the brain as sensations from the vagina, clitoris and cervix.
[46]
Nipple/Breast stimulation and sexual arousal in young men and ...
Manipulation of the nipples/breasts causes or enhances sexual arousal in approximately 82% of young women and 52% of young men with only 7-8% reporting that ...
[47]
Nipple orgasm: What it is, and how to have one - MedicalNewsToday
Aug 6, 2024 · Nipples contain hundreds of nerves, making them sensitive. Evidence confirms that these nerves play a role in arousal and orgasm for both males ...Are nipple orgasms possible? · How to try for a nipple orgasm
[48]
Nipple/Breast Stimulation and Sexual Arousal in Young Men and ...
Manipulation of the nipples/breasts causes or enhances sexual arousal in approximately 82% of young women and 52% of young men with only 7–8% reporting that it ...
[49]
Release of oxytocin and prolactin in response to suckling - PMC - NIH
These results clearly indicate that the milk ejection reflex, with release of oxytocin, occurs in most women before the tactile stimulus of suckling. A second ...
[50]
Mothers are more sensitive to infant cues after breastfeeding ...
Each time the infant suckles at the breast, the direct nipple stimulation causes a neurogenic reflex whereby prolactin is released from the lactotrophs of the ...
[51]
[PDF] Nipple Sucking and Male Sexual Response: Perceived Pleasure ...
Sep 10, 2025 · Nipple sucking may serve dual functions: augmenting erotic stimulation and reinforcing affiliative meanings. (e.g., nurturance, care, play, or ...
[52]
The mammary hair of Monodelphis domestica and homology of the ...
Aug 26, 2024 · Therian mammals, that is, marsupials and placental mammals, evolved nipples as a novel structure. Therian nipples lack hairs in the adult form.<|separator|>
[53]
[PDF] The Mammary Gland and Its Origin During Synapsid Evolution
Lactation appears to be an ancient reproductive trait that predates the origin of mammals. The synapsid branch of the amniote tree that separated from other ...
[54]
The origin and evolution of lactation - PMC - PubMed Central - NIH
Apr 24, 2009 · In response, Darwin hypothesized that mammary glands evolved from cutaneous glands that were contained within the brood pouches in which some ...
[55]
Mammals 'Got Milk' for Past 160 Million Years | Live Science
May 12, 2009 · Mammals' origins go back to mammal-like reptiles called synapsids. The first synapsids occur in the fossil record about 310 million years ago.
[56]
Palaeoneurological clues to the evolution of defining mammalian ...
May 9, 2016 · A fossil record for mammary glands does not exist, and the oldest known fossilized hairs date to the Late Jurassic. Hair-like structures ...
[57]
the fossil record of ontogeny in mammals and their closest relatives
Jan 13, 2010 · The evolution of lactation in mammals is correlated with dental features such as the late eruption of the first functional teeth. Mammals are ...<|control11|><|separator|>
[58]
The coevolution of mammae number and litter size - bioRxiv
Oct 9, 2020 · We show that mammae number and fecundity are fundamentally linked and argue that mammae number likely constrains litter-size evolution.
[59]
The mammary gland and its origin during synapsid evolution
Repeated radiations of synapsids produced a gradual accrual of mammalian features. The mammary gland apparently derives from an ancestral apocrine-like gland ...Missing: empirical | Show results with:empirical
[60]
Why Do Men Have Nipples? - Verywell Health
Sep 3, 2025 · Men have nipples because all embryos develop from the same genetic blueprint before male and female characteristics form.
[61]
Sexual Differentiation - Endotext - NCBI Bookshelf - NIH
Jul 24, 2025 · No sexual difference can be observed in the gonads until the 6th week of embryonic life in humans and 11.5 days post-coitum (dpc) in mice.
[62]
The molecular basis of mammary gland development and epithelial ...
During embryonic development, macrophages invade and partially remove the mammary epithelium of males, implicating the microenvironment in the sexual ...
[63]
Why do men have nipples? - UNSW Sydney
Sep 19, 2019 · The nipples of both enlarge but female nipples enlarge more. At the same time, the ducts of the male breasts shrink while female breasts enlarge ...
[64]
Why Do Men Have Nipples? And 8 Other Questions, Answered
Feb 25, 2019 · Males have nipples because these develop in the womb before embryos develop a sex. By the time a Y chromosome distinguishes a fetus as male, the nipples have ...<|separator|>
[65]
What nipple size means for evolutionary biology | ScienceDaily
Jun 27, 2018 · Researchers show that female nipples are more diverse in size than male nipples -- going against assumptions from evolutionary biology.
[66]
Evolution of Hair Follicles, Mammary Glands, and Sweat Glands in ...
Oct 16, 2015 · Skin appendages such as hair follicles, mammary glands and sweat glands develop during embryonic life through a series of interactions between surface ...
[67]
Anatomy of the lactating human breast redefined with ultrasound ...
The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast.Breast Tissues · Discussion · Fig. 7
[68]
Using Photogrammetry to Analyze Anatomical Changes in the ...
Apr 30, 2024 · Factors related to breast aesthetics, like differences in the height of nipples and the distance from the sternal notch to the nipple, represent ...
[69]
Supernumerary Nipple: Background, Pathophysiology, Etiology
Dec 16, 2024 · The prevalence of supernumerary nipples varies geographically. The prevalence is 0.22% in a Hungarian population, 1.63% in African American ...Background · Pathophysiology · Epidemiology
[70]
Common and Unusual Diseases of the Nipple-Areolar Complex
Oct 1, 2007 · Benign abnormalities may include mammary duct ectasia, nipple calcifications, cutaneous horn of the nipple, abscess of the Montgomery gland, and nipple adenoma.Missing: pathological review
[71]
Multimodality approach to the nipple-areolar complex: a pictorial ...
Aug 5, 2020 · This review describes and illustrates a combined clinical and radiological approach to evaluate the nipple-areolar complex.Missing: peer | Show results with:peer
[72]
Skin diseases of the nipple and areola complex: A case series study ...
The most common diseases were eczema, Paget's disease (PD), adenoma of the nipple (AN), seborrheic keratosis (SK), cutaneous metastasis of breast cancer, wart, ...
[73]
Lesions of the nipple - ScienceDirect.com
Review. Lesions of the nipple · Squamous metaplasia of lactiferous ducts (SMOLD). Other names: recurrent subareolar abscess, Zuska disease, periductal mastitis ...
[74]
Common Breast Problems - AAFP
Apr 15, 2019 · Common breast problems include breast mass, pain, and nipple discharge. Breast symptoms were reported in about 3% of all visits by female patients to family ...
[75]
Mammary Paget Disease - StatPearls - NCBI Bookshelf - NIH
Paget disease of the breast is an unusual and different form of presentation of underlying breast cancer. · Most nipple rashes are simply a minor skin infection ...
[76]
Paget's disease of the breast - Symptoms & causes - Mayo Clinic
Paget's disease of the breast often causes scaly or crusty skin on the nipple. The affected area may slowly grow to involve the skin around the nipple, called ...
[77]
A Review of Anatomy, Physiology, and Benign Pathology of the Nipple
The nipple and areola are pigmented areas of modified skin that connect with the underlying gland of the breast via ducts.Missing: terminology | Show results with:terminology<|separator|>
[78]
Nipple Discharge: Current Clinical and Imaging Evaluation | AJR
Papillomas are the most common cause of pathologic nipple discharge, accounting for 35–58% of cases [23, 24]. They can be classified as solitary intraductal or ...
[79]
Nipple discharge - PMC - NIH
Pathologic nipple discharge is spontaneous and often unilateral. It may arise from a single duct or be associated with a mass or new skin changes. It can be ...
[80]
Nipple Discharge - Gynecology and Obstetrics - Merck Manuals
Nipple discharge can be serous (yellow), mucinous (clear and watery), milky, sanguineous (bloody), purulent, multicolored and sticky, or serosanguineous (pink).
[81]
Workup and treatment of nipple discharge—a practical review
In this review, we present an overview of the treatment and management of pathologic nipple discharge (PND).
[82]
Congenital Anomalies of the Breast - PMC - NIH
Other congenital breast anomalies include supernumerary nipple and areola (polythelia) and breast (polymastia), which can generally be found on the ...
[83]
Clinical abnormalities of the nipple-areola complex
The main differential diagnoses are erosive adenomatosis and eczema of the nipple. Acquired inverted nipple is generally of inflammatory origin. It is usually ...
[84]
Evaluation of Breast Disorders - Gynecology and Obstetrics
Each breast is inspected for irregularities in shape (bulging, irregular contour), nipple abnormalities (inversion, retraction, discharge, crusting), and skin ...
[85]
Nipple: Anatomy & Types - Cleveland Clinic
Jan 7, 2025 · Nipple appearance · Protruding. Your nipples stick outward from your areola and look a bit like tiny cylinders. This is the most common type.
[86]
Paget's disease of the nipple - NHS
Around half of all women diagnosed with Paget's disease of the nipple have a lump behind the nipple. In 9 out of 10 cases this is an invasive breast cancer.Diagnosis · Treatment · Reducing the risk
[87]
Paget Disease of the Breast - NCI - National Cancer Institute
Apr 10, 2012 · What are the symptoms of Paget disease of the breast? · Itching, tingling, or redness in the nipple and/or areola · Flaking, crusty, or thickened ...<|separator|>
[88]
Breast imaging in patients with nipple discharge - PMC
The clinical examination is an essential part of the patient evaluation, allowing benign nipple discharge to be distinguished from suspicious nipple discharge, ...
[89]
Breast Exam | Stanford Medicine 25
The physical exam of the breast can be divided into three components: inspection, palpation and lymph node exam.
[90]
Nipple Ultrasound: A Pictorial Essay - PMC - PubMed Central
A nipple can be either hypovascular or hypervascular on color Doppler US. Vascular symmetricity a key feature to distinguish normal and pathological nipples.
[91]
8 Causes of sore nipples: Symptoms, treatments, and more
Common causes of sore nipples include friction caused by clothing during exercise, an infection, eczema, sexual contact, hormonal changes, pregnancy, and ...
[92]
Breast Pain: 10 Reasons Your Breasts May Hurt
Hormonal fluctuations are the number one reason women have breast pain. Breasts become sore three to five days prior to the beginning of a menstrual period and ...
[93]
Understanding Nipple Pain: Causes, Treatment, and More - Healthline
Your nipples can hurt for many reasons. Some causes are as benign as a poorly fitting bra. Others, like breast cancer, are more serious.Causes · Treatment · Diagnosis · In breastfeeding
[94]
Why Do My Nipples Hurt? 11 Causes and Treatments
Aug 24, 2025 · Nipples may hurt due to—among other reasons—hormonal changes, allergies, irritation, or, in rare cases, Paget's disease, which is associated ...
[95]
Why Do My Nipples Hurt? - WebMD
Nov 22, 2024 · Nipples are sensitive, and they can hurt for lots of reasons. Tight clothes, rashes, and infections can all irritate the tender skin.
[96]
Seven Possible Causes of Nipple Pain in Men | Banner Health
Nov 14, 2023 · Medical conditions like eczema, contact dermatitis, allergic reactions and psoriasis can affect the skin around the nipple area. You might ...
[97]
https://www.goodrx.com/conditions/pain/why-are-my-nipples-sore
[98]
Nipple Discharge: Color, Causes, What It Means & Treatment
Hormones, lactation or sexual arousal can be normal causes for nipple discharge. Abnormal causes could be from tumors, infection or rarely, breast cancer.Missing: pathological | Show results with:pathological
[99]
Breast Nipple Discharge - StatPearls - NCBI Bookshelf
Jun 26, 2023 · Infection (periductal mastitis) · Breast abscess · Neoplastic process of the breasts (e.g., intraductal carcinoma, Paget disease of breast).Breast Nipple Discharge · Etiology · History And Physical
[100]
Nipple discharge: MedlinePlus Medical Encyclopedia
Oct 17, 2024 · Nipple discharge may be a symptom of breast cancer or a pituitary tumor. Skin changes around the nipple may be caused by Paget disease. When ...
[101]
Nipple discharge Causes - Mayo Clinic
Causes · Abscess. · Birth control pills. · Breast cancer · Breast infection. · Ductal carcinoma in situ (DCIS) · Endocrine conditions. · Fibrocystic breasts ...
[102]
Nipple discharge - UpToDate
Feb 12, 2024 · TYPES AND CAUSES OF NIPPLE DISCHARGE · Lactation · Physiologic nipple discharge (galactorrhea) · Pathologic (suspicious) nipple discharge.<|separator|>
[103]
Common Breast Problems - AAFP
Aug 15, 2012 · The first step in the diagnostic workup for patients with nipple discharge is classification of the discharge as pathologic or physiologic.
[104]
Mammary Paget's Disease of the Nipple: Relatively Common but ...
Mammary Paget's disease is a known cause of eczematous lesions of the nipple with an incidence of 1% of all breast cancers.
[105]
Paget's Disease of the Nipple | Magee-Women's Hospital - UPMC
Paget's disease of the nipple is a rare type of breast cancer affecting the nipple and the areola (the circle of skin surrounding the nipple).
[106]
Nipple Areola Complex Involvement in Invasive Carcinoma Breast
Feb 8, 2018 · A variety of factors including tumor biology and distance of the tumor from the nipple have been associated with nipple areola complex involvement in patients ...
[107]
Occult Nipple Involvement in Breast Cancer - ASCO Publications
Aug 31, 2009 · Most nipples that were involved by invasive carcinoma showed direct extension of invasive tumor into the retroareolar region and the nipple ...
[108]
Nipple-Invasive Primary Carcinomas: Clinical, Imaging, and ...
Feb 12, 2018 · Rare, invasive, primary nipple carcinomas typically present as subtle nipple thickening or an exudative crust on the skin.Paget Disease With Invasion... · Invasive Carcinoma Arising... · Discussion
[109]
Mammographic distance as a predictor of nipple-areola complex ...
The mammographic distance between the tumor and the nipple is independently predictive of NAC involvement and is useful as an equation variable.
[110]
Tumor-to-nipple Distance Should Not Preclude Nipple-sparing ...
A great concern is related to the risk of nipple-areola complex (NAC) involvement which may occur in up to 20% of patients, although these figures are reduced ...
[111]
Nipple adenoma - Breast - Pathology Outlines
Aug 28, 2023 · Nipple adenoma is a benign breast lesion and can consist of sclerosing adenosis, papillary hyperplasia and epithelial hyperplasia, which can be ...<|separator|>
[112]
Rare benign tumours of the nipple - PubMed
Four cases of rare benign nipple tumours: neurofibromas, wart, leiomyoma and milium are presented.
[113]
Nipple-Sparing Mastectomy Long-Term Outcomes: Early and Late ...
Apr 8, 2020 · As shown in Table 2A, the main early complication was the necrosis of the nipple–areola complex found in 6.4%, while the less detected was the ...
[114]
Nipple sparing mastectomy techniques: a literature review and an ...
In the studies reviewed, incision placement, away from the nipple, resulted in the lowest rates of ischemic nipple complications and the best cosmetic outcomes.
[115]
[PDF] 5-year outcomes of nipple-sparing versus skin-sparing mastectomy
Of the 1094 nipple-sparing mastectomy procedures for cancer, 2 patients had a nipple areola complex recurrence.
[116]
The “Five-flap” Technique for Nipple–Areola Complex Reconstruction
Nov 4, 2021 · The local flap is the most frequently used technique for nipple reconstruction. It is generally performed 4–6 months after mastectomy, as an ...
[117]
Nipple Reconstruction Using the C-V Flap Technique: Long-Term ...
CV flap nipple reconstructions provide a simple and reliable method to reconstruct the nipple that enhances confidence and perception of body image.
[118]
Review of Nipple Reconstruction Techniques and Introduction of V ...
Apr 6, 2015 · The method is easy to perform, reproducible, has low operative morbidity, and incorporates previous wise pattern mastectomy or mammaplasty scars ...
[119]
Double Triangle Suture Technique for Inverted Nipple Correction ...
Double triangle suture technique is a safe and reliable inverted nipple correction method. It requires two small incisions, few sutures, and minimal operation ...
[120]
Surgical Correction of Inverted Nipples - PMC - PubMed Central
Jul 27, 2020 · Nipple inversion is a common pathologic condition affecting 2%–10% of women. Congenital inversions are the most common forms, while acquired ...Surgical Strategies · Table 3 · Table 4Missing: related | Show results with:related
[121]
Current surgical techniques for nipple reduction: A literature review
Jul 4, 2019 · Five different techniques were described, namely, circumcision, amputation, wedge resection, simple grafting and flaps. Patient satisfaction rates were high.
[122]
Gynecomastia Surgery Procedure Steps | ASPS
Excision also is necessary if the areola will be reduced or the nipple will be repositioned to a more natural male contour.Cost · Gynecomastia Surgery · Risks and Safety · Candidates
[123]
Successful Excision of Gynecomastia with Nipple Repositioning ...
We excised the gynecomastia with nipple repositioning utilizing the dermoglandular flap (about 1 cm thickness and 10 cm width). After one month, no complication ...
[124]
Why Are Women's Nipples Banned in Public and on Instagram, but ...
Jul 10, 2015 · Women's nipples are considered obscene, indecent, lewd, banned on Instagram and other social media, and against the law in most places.
[125]
Penises, Nipples, and Bums, Oh My!: An Examination of How ...
It is completely constitutional for the government to prevent women from publicly showing their nipples in order to protect morality and public order. Thus, ...
[126]
Court upholds ordinance prohibiting women, but not men, from ...
Jul 1, 2019 · The ordinance prohibited the exposure of “the female breast with less than a fully opaque covering of any part of the areola and nipple.” The ...
[127]
The Weird, Wild Legal History of Breasts and Nipples - Yahoo
Dec 12, 2014 · In Arizona, a woman can be arrested for indecent exposure if she exposes the areola or nipple of her breast if someone else is present.
[128]
Free the Facts: There Is No Constitutional Right To Be Topless In ...
Oct 15, 2019 · Being topless in public is not inherently expressive activity. As such, laws prohibiting women from being topless in public do not violate the 1st Amendment.<|separator|>
[129]
Nipple ban on Instagram and Facebook reveals how bizarre our ...
Feb 3, 2023 · The history of nipple censorship. Across many western cultures, exposed female nipples are seen as taboo, indecent and sometimes even illegal.
[130]
Free the Nipple States 2025 - World Population Review
The movement challenges the convention that men are allowed to be topless in public while it is considered indecent or sexual for women to do the same.<|separator|>
[131]
Free the Nipple: A History of a Hidden Movement - Hyperallergic
Oct 5, 2021 · While court cases have helped to shape this movement from the 1930s until today, the social-media landscape has generally remained deaf to ...
[132]
The History of Toplessness - VICE
Aug 24, 2015 · The Enlightenment was when toplessness started becoming taboo; until around the year 1700, toplessness was quite a bit more common than it is ...Missing: norms | Show results with:norms
[133]
The Social Area of the Breast: An Evolution Through Cultures ... - NIH
Ancient Times, Breast exposure equated as symbol of fertility and beauty, with Greek and Roman clothing often featuring draped garments that left the breasts ...
[134]
Breastfeeding in Public: Why So Taboo?: Women's Health ...
Jan 3, 2024 · In 49 states, the District of Columbia and the Virgin Islands, mothers are within their legal right to breastfeed in any public or private ...
[135]
It's okay to breastfeed in public but… |
Jun 11, 2019 · Breastfeeding in public requires women to be discrete and covered-up, so as not to expose her breast. She is also required to feed in an appropriate place.
[136]
(PDF) Nudity Norms and Breast Arousal: A Cross-Generational ...
Our study thus provides preliminary evidence that men's sexualization of female breasts might have cross-cultural, evolutionary grounds.
[137]
https://purushu.com/2015/12/modesty-gender-specific-nudity-norms.html
[138]
How to Have a Nipple Orgasm: 23 Tips for You and Your Partner
And playing with your nipples can bring you a lot of pleasure. When your nipples are stimulated, they shoot off sparks in the genital sensory cortex. This is ...Best Nipple Clamps · Curious About Sex Toys? Find... · That big O · Sex toys
[139]
Women's Physical and Psychological Responses during Penetrative ...
These findings suggest that breast and nipple stimulation may act as both physical arousal enhancers and emotional regulators during penetrative sex. This paper ...<|separator|>
[140]
Male nipple erection engenders similar emotions as female nipple ...
Oct 6, 2022 · Levin and Meston (2006) reported that for 52% of men nipple stimulation was sexually arousing and 39% reported it increased their sexual arousal ...
[141]
The Female Nipple and Art History - athena art foundation
A woman's breasts said more about her status in society than it did about sexuality. In fact, a young woman showing off her breasts implied innocence and purity ...
[142]
Free the Nipple, says History - Messy Nessy Chic
Oct 16, 2024 · The exposure of one breast typically symbolised high birth and strong moral character. There was no shame and no explicit message of sexual ...
[143]
'A wild cocktail of emotion, politics and desire': the history of breasts ...
May 6, 2024 · Think of the history of women's necklines in Europe as a microcosm of the way breasts were socially coded: the high ruffs in early Elizabethan ...
[144]
Complications associated with intimate body piercings - PubMed
Nipple piercings can hinder breast feeding by inhibiting the milk letdown reflex, increasing nipple sensitivity, and causing discomfort to the infant. Removal ...
[145]
Nipple piercing overview - Salamander Jewelry Blog
Feb 21, 2025 · Many an apocryphal nipple piercing tale appears to stem from the works of Doug Malloy – the pseudonym of one Richard Simonton.
[146]
Piercings: How to prevent complications - Mayo Clinic
An infection can cause redness, pain and swelling after a piercing. A fluid that looks like pus also may come out of the pierced hole when there's an infection.
[147]
The Victorians Wore Nipple Rings
Feb 5, 2022 · Some believed that the nipple rings would cause scars that turned cancerous. Some male doctors hated the idea that the women getting piercings ...
[148]
The Titillating Rise of Nipple Piercings - VICE
Oct 6, 2016 · “Three thousands years ago, in ancient Egypt, high-status women enjoyed covering their nipples lavishly with gold paint,” zoologist Desmond ...
[149]
Body Piercing Infections - StatPearls - NCBI Bookshelf - NIH
Localized cellulitis is the most common infectious complication resulting from body piercings. This activity reviews the evaluation and treatment of body ...
[150]
Nipple Piercing - Drugs and Lactation Database (LactMed®) - NCBI
Jun 21, 2021 · Piercing of the nipples seems to not interfere with lactation in most cases,[1,2] although poor latching, and milk leakage from the infant's mouth have been ...
[151]
Invasive ductal carcinoma at the site of a cosmetic nipple piercing
Mar 12, 2025 · The procedure of piercing the nipple while usually safe, can result in acute and chronic complications [1]. The average lifetime risk of ...
[152]
Nipple and Areola Tattoos After Breast Cancer Surgery
Nov 2, 2022 · Photos show before and after images of nipple and areola tattoos done by MSK specialists after 3D tattoo: Bilateral implant reconstruction.
[153]
Nipple Tattoos and Nipple Reconstruction Surgery - Breastcancer.org
Feb 18, 2025 · Between 4 to 6 months after nipple reconstruction surgery, you can have tattoos applied to the reconstructed nipple(s) and areola(s) to add ...
[154]
Nipple & Areola Reconstruction: Surgery & Tattoo Options
Oct 25, 2023 · Many people undergo nipple reconstruction after a mastectomy. Nipple tattoos heal quicker than surgery and don't require an anesthetic.
[155]
Expanding Access to Nipple-areola Tattooing as a Component ... - NIH
Nov 27, 2019 · Tattooing alone is at times the only option for nipple-areola reconstruction in patients who may have damaged tissue due to radiation therapy or ...<|control11|><|separator|>
[156]
https://sistersrepublic.eu/en/blogs/der-blog-der-sisters/free-the-nipple-eine-hochst-umstrittene-feministische-bewegung
[157]
A Question of… Discrimination - The Philosophers' Magazine -
The question at stake: should women be allowed to expose their nipples on the platform? Currently men can show their nipples and women can't.
[158]
Free the Nipple Movement Shows the Banality of Modern Feminism
Jun 22, 2015 · Free the Nipple activists accuse society of a double standard for allowing men to show their breasts but not women.
[159]
Minnesota Supreme Court Legalizes Nonsexual Toplessness - Reddit
May 5, 2025 · In short, the Court unanimously held that a woman who is topfree is not acting lewdly merely by appearing in public with her torso unclothed.US map showing state-by-state legality of toplessness for femalesCMV: Women's Toplessness Should Be Legal and Not Censored ...More results from www.reddit.comMissing: controversies | Show results with:controversies
[160]
Laws on Female Toplessness Across U.S. States and Territories
Jan 14, 2025 · Women can legally go topless in 6 states, after federal ruling. Oklahoma, Wyoming, Utah, Colorado, New Mexico, and Kansas. These states are ...Missing: controversies | Show results with:controversies
[161]
Male or female? Genderless Nipples account challenges ...
Jan 19, 2017 · Instagram bans female nipples, but closeup images make it difficult – if not impossible – to tell whether they are male or female.
[162]
We The Nipple - National Coalition Against Censorship
Oct 31, 2024 · NCAC calls on Facebook and Instagram to respect artists and revise terms of service to allow artistic photographic nudity. We The Nipple.
[163]
Facebook's Censoring of Women's Bodies is Nipocrisy - Hyperallergic
Aug 30, 2021 · Facebook guidelines prohibit “uncovered female nipples,” making a female-presenting body twice as likely as a male-presenting body to be flagged as obscene.
[164]
Breastfeeding in public: “You can do it?” - PMC - PubMed Central
On a regular basis there is an outcry about a mother who has been told to cover up or move away from a public area while she is breastfeeding.
[165]
Breastfeeding in public explained, even though we shouldn't have to
Aug 1, 2019 · Breastfeeding moms have been asked to cover up at pizzerias, confronted at malls, singled out on flights and booted from water parks. So I ...
[166]
Barriers to Breastfeeding in the United States - NCBI - NIH
When they have breastfed in public places, many mothers have been asked to stop breastfeeding or to leave. Such situations make women feel embarrassed and ...
[167]
Florida City Hall U-Turns Censoring Nipples in Cancer Survivor Art ...
Jul 24, 2024 · The controversy began when a government official allegedly removed one of the paintings without permission, according to Isaiah Haddon, a vocal ...
[168]
'The nipple has not been freed! The art world must continue to fight ...
Apr 10, 2023 · Social media giant has been taken to task for its notorious “female nipple” guideline, but the battle for creatives' freedom of expression is not yet over.
[169]
A brief history of nipple censorship and why it matters - Cosmopolitan
Jun 13, 2023 · “Female nipples nourish our young, yet they are sexualised and sensualised to the point they are censored. All embryos have nipples from ...