Nipple overflow is divided into physiological nipple overflow; medication nipple overflow; systemic disease causing nipple overflow; and breast disease causing nipple overflow. Physiological nipple overflow is mostly bilateral nipple overflow. If there is a small amount of pulpy nipple overflow before and after menstruation; in the middle and late stages of pregnancy, some pregnant women can squeeze out a little light colored colostrum from both breasts; when women enter menopause, due to endocrine disorders, some women will secrete a small amount of breast milk Drug-induced nipple overflow Drug-induced nipple overflow, mostly bilateral overflow, the main drugs are: oral contraceptives, neuropsychiatric drugs such as carbamazepine, chlorpromazine; digestive system drugs such as cimetidine, gastrodin, cardiovascular drugs. The main drugs are: oral contraceptives, neuropsychiatric drugs such as carbamazepine and chlorpromazine; digestive system drugs such as cimetidine and gastrofluan; cardiovascular drugs such as captopril and reserpine. Systemic diseases that cause nipple discharge are mainly due to increased serum prolactin levels caused by various reasons, such as pituitary tumors, endocrine pathologies (including endocrine disorders, thyroid disorders, ovarian or adrenal tumors, etc.). Other systemic diseases such as hemophilia, purpura, etc. Breast diseases causing nipple overflow Cystic hyperplasia of the breast; Ductal dilation of the breast ; Intraductal papilloma ; Intraductal papillary carcinoma: Unilateral uniportal hemorrhagic overflow, breast cancer is more likely. Symptoms should be promptly seen in hospital for cytological examination of overflow smear. Infrared breast scan, ultrasound examination and mammogram have considerable accuracy. Selective lesion ductography or lactoscopy is also available.