As the name implies, nipple discharge is running water from the nipples. Women who have experienced childbirth and breastfeeding are very familiar with nipple discharge, which is actually a kind of overflow, but of course we are more concerned about non-breastfeeding overflow. 1. What is the difference in the nature of nipple discharge? There are many different kinds of overflow when you look at the color traits. The most common is milk-like, there are also yellowish or clear colorless ones (which we call plasma), and some will appear as red or brown bloody overflows. A few others have very thick, toothpaste-like spills, similar to the oil squeezed out of acne. If there is inflammation in the breast, pus may be secreted. The discharge comes from the small milk duct opening on the nipple. Close observation will show that in some people the discharge comes from the same milk duct, while in many people it appears as a multi-pore discharge, or even a multi-pore discharge from both breasts. The amount of overflow may also vary. Some people have very little overflow and need to squeeze hard to get it, or it may just occasionally stain their underwear. Others have a larger amount of overflow, which is noticeable with a gentle squeeze. There are also long and short periods of time, some people have only had one or two, while others may last for several years. 2. What are the possible diseases of nipple overflow and do the different traits mean different diseases? From the nature of the overflow, the water “overflowing” may be milk, blood or plasma tissue fluid, or scum. Under physiological conditions, normal breasts secrete a small amount of milk or mucus, especially after breast stimulation, so the occasional small amount of milk-like or plasma overflow is physiological and not a cause for concern. Some people have other diseases, such as pituitary tumors, or thyroid disorders, which can lead to an increase in the hormones in charge of milk secretion, and this may result in persistent lactation, mostly in larger amounts, and mostly in bilateral porous overflows. In other cases, lactation can be caused by oral medications, such as certain stomach medications, psychotropic drugs and some diuretics. These lactating patients do not actually have any breast lesions and all they need to do is to remove the triggering factors. Many young women experience pain in the breasts, especially in the areola area, and the nipples may secrete a small amount of toothpaste-like material, which is similar to acne in that it is caused by poor discharge of a small amount of lipid from the usual glands. If not treated in time, it may develop into mastitis. We call the overflow that may be tumor-related pathological overflow. The tumors mentioned here include breast cancer and intraductal papilloma. Most of these tumors occur from the lining of the milk ducts, and the rupture of small blood vessels on the surface of the tumor can cause a bloody overflow. If the tumor is close to the nipple and the blood drains quickly, it is a relatively bright red color, while if it is far from the nipple, it may be black or brown. In most cases, pathological overflow is manifested as a unilateral single hole. 3. What tests are available for nipple overflow? Milk-like overflow is basically not a problem or simply a manifestation of other diseases. Most pathological overflows are benign, mainly including intraductal papilloma and ductal dilatation, and less than 10% of patients have breast cancer. 4.Does nipple overflow need surgery? Can medications be effective? Surgery is required for all pathological overflows, that is, unilateral single-hole persistent bloody or plasma overflows. The purpose of surgery is mainly for diagnosis, if it is benign then it can be observed, if it is cancer then treatment should be continued according to the principles of breast cancer. The vast majority of overflows do not require medication, except for some hormonal abnormalities causing lactation that may require medication, which is also ineffective.