Nipple overflow is a common symptom of breast disease and can be divided into physiological overflow and pathological overflow. Physiologic overflow refers to lactation during pregnancy and lactation, bilateral nipple overflow caused by oral contraceptives or sedatives, and unilateral or bilateral small amounts of overflow in postmenopausal women. Pathological overflow refers to natural overflow from one or more ducts on one or both sides that is not physiologically related to pregnancy and lactation. Intermittent and persistent nipple overflow from several months to several years is mainly referred to as pathological overflow. Nipple discharge is often unilateral and can occur on both sides of the ducts simultaneously. Unilateral single duct nipple overflow is common in intraductal papilloma unilateral multiductal overflow is common in ductal dilatation of the breast, cystic hyperplasia of the breast; bilateral multiductal overflow is seen in endocrine disorders, drug reactions, amenorrhea-overflow syndrome or certain benign diseases of the breast. 1, nipple overflow can be divided into the following categories: (1) milk-like fluid: the color of the overflow resembles de-fatted milk. It is common in amenorrhea-overflow syndrome (breast overflow), anterior pituitary hyperfunction syndrome, or after taking oral contraceptives due to the pituitary gland being inhibited from releasing too much prolactin, and some patients with mastocytosis can also appear at this time, often for both sides of the multi-tubular overflow, automatic outflow. (2) Pimple-like overflow: mostly caused by ductal dilatation of the breast, the patient mostly has congenital nipple indentation, the nipple has a lipid pimple-like discharge with a foul odor overflow. This type of overflow is viscous and mixed with many colors and spontaneously overflows. Usually also bilateral multitubular patients are often accompanied by burning, swelling, itching, also seen in menopausal or young and middle-aged women with hypogonadism. (3) watery fluid: the overflow is thin like water mostly caused by diseases such as intraductal papilloma, cystic hyperplasia of the breast and breast cancer Recently it is believed that about 50% of watery overflow may be cancer (4) purulent fluid: the overflow resembles pus and is commonly seen in postpartum acute mastitis breast abscesses. (5) Plasma fluid: light yellow in most cases caused by intraductal papilloma in the lower nipple, also seen in cystic hyperplasia of the breast, ductal dilatation of the breast and breast cancer. (6) Bloody fluid or plasma-bloody fluid: Bloody fluid is red, plasma-bloody is pink. Bloody fluid is more common with intraductal papilloma. If a patient over 50 years old has unilateral bloody nipple overflow, it often suggests that it may be intraductal papillary carcinoma and should be given high priority. Plasma hematochezia can be caused by either intraductal papilloma or cystic hyperplasia of the breast or intraductal papillary carcinoma. (7) Light green overflow: the secretion is a light colored lighter green liquid 2, nipple overflow examination methods (1) ultrasound examination This method can be used to diagnose the cause of benign breast disease at a rate of up to 80% to 90%, ultrasound examination can see enlarged milk ducts, very small cysts, and sometimes intraductal papilloma or filling defect situation, the diagnosis of malignant breast disease at a rate of up to 71% to 90%. It has been reported that the combined application of universal B-ultrasound and color Doppler ultrasonography can greatly improve the diagnostic compliance rate of breast diseases This method is non-invasive, painless, simple and easy for patients with the advantages of high resolution. (2) Selective ductography has a greater diagnostic value for both benign and malignant breast diseases with nipple overflow, especially for those who have nipple overflow without lumps and other features on physical examination, or whose other tests are negative. Selective mammography can clarify the site, nature and degree of overflow before surgery. 3, treatment of nipple overflow (1) Treatment of non-tumor overflow: often caused by breast duct dilatation cystic hyperplasia of the breast, etc. The former can be treated with medication or surgery, and the latter can be treated with herbal medicine, medication or surgery. (2) Treatment of tumor overflow: It is often caused by intraductal papilloma or intraductal papillary carcinoma. In the former case, local segmental excision should be performed, and in the latter case, radical mastectomy for breast cancer should be performed.