Benign breast disease includes mastalgia, fibrocystic breast disease (FBD), breast cellulites and abscesses, nipple discharges, and galactorrhea. FBD is the most common benign breast disease. FBD starts as microcysts and accompanying fibrosis in 65% of women. The cysts become larger as the woman ages, and can reach 3 to 4 cm. Breast infections can affect the skin, producing a primary cellulitis, or may be secondary to an infection of a sebaceous gland, axillary gland, or lymph node, such as in hidradenitis supparativa. Most mastitis occurs in breast-feeding women. Nipple discharges are the third most common complaint concerning 5% of women attending breast clinics. Discharges associated with a breast mass are more likely to be related to cancer. Diseases that affect the hypothalamic and pituitary areas such as sarcoidosis, tuberculosis, histocytosis, and multiple sclerosis can cause galactorrhea. Galactorrhea is often physiological or caused by medication or treatable hormonal disorders.