Breast, disorders of the

Disorders affecting the breast that are mostly minor and respond readily to treatment. The most important causes of problems are infection, such as mastitis, tumours, and hormonal changes. Breast cysts, fibroadenomas, other noncancerous tumours, or, more rarely, breast cancer may occur. Breast pain and tenderness is common just before menstruation or when a woman is taking hormones. Before menstruation, breasts may become bigger and lumpy. Such lumps shrink when menstruation is over. Hormonal disorders may, rarely, cause galactorrhoea (abnormal milk production). In men, gynaecomastia may result from hormonal disturbance or treatment with certain drugs.