Hair growth on men’s breasts may be caused by genetics, medications, hirsutism and other factors. 1. Heredity: Hair growth is related to genetic factors, and hair growth on men’s breasts may be determined by genetic predisposition. 2. Drugs: androgens will promote hair growth, men taking drugs containing androgens such as testosterone, etc., may appear breast hair growth; long-term large amounts of glucocorticoids such as dexamethasone, may also lead to breast hair growth. 3. Hirsutism: This disease is related to Cushing’s syndrome, dermatomyositis and other factors, patients may have excessive hair growth symptoms, such as the chest, around the nipples and so on. Men who have breast hair growth can consult a doctor in time, under the guidance of the physician for related treatment.