Whether nipple overflow for 15 years is serious depends on the nature of the overflow, symptoms, etc. However, 15 years is a long time and treatment is recommended. 1. White nipple discharge: it may be caused by lesions in the pituitary gland and increased prolactin, and is usually mild. 2. Yellow plasma nipple discharge: most commonly seen in breast hyperplasia. If there is breast tenderness and unclear demarcation with the surrounding, the situation is relatively serious. 3. Bloody nipple discharge: It can be seen in breast cancer, intraductal papilloma and other diseases, and the appearance of the breast may be changed. With symptoms such as swelling and pain, the situation is usually more serious. Whichever of the above cases, it is recommended to consult a doctor in time to find out the cause of the disease and treat it as early as possible in order to have a chance to cure it.