Nipple discharge is the second most common clinical symptom in breast surgery clinics. The color of the discharge varies and is commonly milky white, clear and colorless, yellowish, bright red and brown. Generally speaking, milky white, clear and colorless, and yellowish are common causes such as dilated milk ducts and ductitis, which do not require special treatment. Bright red and brown are common because of intraductal papilloma, which is a benign disease but is prone to cancer, so surgery is usually required. The most critical aspect of surgery for intraductal papilloma is localization because the tumor grows inside the breast duct and is very small, so it is not easily detected by general examinations, including hand examination by doctors, ultrasound and mammography, so mammography is needed to help localize it. Single intraductal lesions are not likely to recur after surgery, while multiple intraductal breast lesions are prone to recurrence, so attention should be paid to localization and review. If you find nipple overflow, especially when it is bright red and brown, you generally need to seek medical attention in a timely manner. Do not squeeze your nipples by yourself, because many examinations are based on the overflowing ducts that have been located, and you cannot locate them by squeezing the water dry by yourself, and usually wear light-colored underwear.