The breasts are two prominences located on the upper ventral region of the torso among humans and other primates. Both sexes develop breasts from the same embryological tissues. The relative size and development of the breasts is a major secondary sex distinction between females and males. There is also considerable variation in size between individuals. Female humans are the only mammals which permanently develop breasts at puberty; all other mammals develop their mammary tissue during the latter period of pregnancy; at puberty, estrogens, in conjunction with growth hormone, cause permanent breast growth.
A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during puberty—and include enlarged breasts and widened hips of females, facial hair and Adam's apples on males, and pubic hair on both. In non-human animals, they can start to appear at sexual maturity—and include, for example, the manes of male lions, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes.
Mastectomy is the medical term for the surgical removal of one or both breasts, partially or completely. A mastectomy is usually carried out to treat breast cancer. In some cases, women believed to be at high risk of breast cancer choose to have the operation as a preventive measure. Alternatively, some women can choose to have a wide local excision, also known as a lumpectomy, an operation in which a small volume of breast tissue containing the tumor and a surrounding margin of healthy tissue is removed to conserve the breast. Both mastectomy and lumpectomy are referred to as "local therapies" for breast cancer, targeting the area of the tumor, as opposed to systemic therapies, such as chemotherapy, hormonal therapy, or immunotherapy.
The nipple is a raised region of tissue on the surface of the breast from which, in lactating females, milk from the mammary gland leaves the body through the lactiferous ducts to nurse an infant. The milk can flow through the nipple passively, or it can be ejected by smooth muscle contractions that occur along with the ductal system. The nipple is surrounded by the areola, which is often a darker colour than the surrounding skin.
Masculinizing gender-affirming surgery for transgender men or transmasculine non-binary people includes a variety of surgical procedures that alter anatomical traits to provide physical traits more comfortable to the trans man's male identity and functioning.
Breast augmentation and augmentation mammoplasty is a cosmetic surgery procedure, which uses breast-implants and/ or fat-graft mammoplasty technique to increase the size, change the shape, and alter the texture of the breasts. Although in some cases augmentation mammoplasty is applied to correct congenital defects of the breasts and the chest wall in other cases it is performed purely for cosmetic reasons.
Reduction mammoplasty is the plastic surgery procedure for reducing the size of large breasts. In a breast reduction surgery for re-establishing a functional bust that is proportionate to the patient's body, the critical corrective consideration is the tissue viability of the nipple–areola complex (NAC), to ensure the functional sensitivity and lactational capability of the breasts. The indications for breast reduction surgery are three-fold – physical, aesthetic, and psychological – the restoration of the bust, of the patient's self-image, and of the patient's mental health.
Paget's disease of the breast is a rare skin change at the nipple nearly always associated with underlying breast cancer. Paget's disease of the breast was first described by Sir James Paget in 1874. The condition is an uncommon disease accounting for 1 to 4% of all breast cancers cases. 92% to 100% of patients with Paget's disease of the breast have an underlying breast cancer.
An inverted nipple is a condition where the nipple, instead of pointing outward, is retracted into the breast. In some cases, the nipple will be temporarily protruded if stimulated. Both women and men can have inverted nipples.
The intermammary cleft, intermammary sulcus, or sulcus intermammarius is a surface feature of males and females that marks the division of the two breasts with the sternum (breastbone) in the middle. The International Federation of Associations of Anatomists (IFAA) uses the terms "sulcus intermammarius" or "intermammary cleft" when referring to the area between the breasts.
Chest reconstruction refers to any of various surgical procedures to reconstruct the chest by removing breast tissue or altering the nipples and areolae in order to mitigate gender dysphoria. Chest reconstruction may be performed in cases of gynecomastia and gender dysphoria. People may pursue chest reconstruction, also known as top surgery, as part of transitioning.
Breast hypertrophy is a rare medical condition of the breast connective tissues in which the breasts become excessively large. The condition is often divided based on the severity into two types, macromastia and gigantomastia. Hypertrophy of the breast tissues may be caused by increased histologic sensitivity to certain hormones such as female sex hormones, prolactin, and growth factors. Breast hypertrophy is a benign progressive enlargement, which can occur in both breasts (bilateral) or only in one breast (unilateral). It was first scientifically described in 1648.
Mastopexy is the plastic surgery mammoplasty procedure for raising sagging breasts upon the chest of the woman, by changing and modifying the size, contour, and elevation of the breasts. In a breast-lift surgery to re-establish an aesthetically proportionate bust for the woman, the critical corrective consideration is the tissue viability of the nipple-areola complex (NAC), to ensure the functional sensitivity of the breasts for lactation and breast-feeding.
Amastia refers to a rare clinical anomaly in which both internal breast tissue and the visible nipple are absent on one or both sides. It affects both men and women. Amastia can be either isolated or comorbid with other syndromes, such as ectodermal dysplasia, Syndactyly and lipoatrophic diabetes. This abnormality can be classified into various types, and each could result from different pathologies. Amastia differs from amazia and athelia. Amazia is the absence of one or both mammary glands but the nipples remain present, and athelia is the absence of one or both nipples, but the mammary gland remains.
Ptosis or sagging of the female breast is a natural consequence of aging. The rate at which a woman's breasts drop and the degree of ptosis depends on many factors. The key factors influencing breast ptosis over a woman's lifetime are cigarette smoking, her number of pregnancies, higher body mass index, larger bra cup size, and significant weight change. Post-menopausal women or people with collagen deficiencies may experience increased ptosis due to a loss of skin elasticity. Many women and medical professionals mistakenly believe that breastfeeding increases sagging. It is also commonly believed that the breast itself offers insufficient support and that wearing a bra prevents sagging, which has not been found to be true.
Tuberous breasts are a result of a congenital abnormality of the breasts which can occur in both men and women, one breast or both. During puberty breast development is stymied and the breasts fail to develop normally and fully. The exact cause of this is as yet unclear; however, a study in 2011 of the cells in the breasts of both males and females with tubular breasts suggested a genetic link in a disorder of collagen deposition. The condition is thought to affect one to five per cent of breast augmentation patients; however, the proportion of the general population affected is unknown as surgery is not always sought.
Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female's life.
Supernumerary nipples–uropathies–Becker's nevus syndrome is a skin condition that may be associated with genitourinary tract abnormalities. Supernumerary nipples, also referred to as polythelia or accessory nipples, is a pigmented lesion of the skin that is present at birth. This pigmentation usually occurs along the milk lines, which are the precursors to breast and nipple development. Clinically, this congenital condition is generally considered benign, but some studies have suggested there may be an association with kidney diseases and cancers of the urogenital system.
SPAIR is a short-scar breast surgery technique developed by Dennis C. Hammond, assistant professor of surgery at Michigan State University. The technique was designed to allow a better-shaped breast, a limited amount of scarring, and a more accelerated healing process, by eliminating the lateral scar beneath the breast found in conventional breast reduction surgery. The technique is considered to be a good alternative to vertical mammoplasty.
Gynecomastia is the non-cancerous enlargement of one or both breasts in men due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Physically speaking, gynecomastia is completely benign, but it is associated with significant psychological distress, social stigma, and dysphoria.
