1.Plasmacytic overflow is mostly seen in intraductal papilloma and mastopathy, also seen in ductal dilatation, and rarely caused by breast cancer. Plasmacytosis is related to a variety of breast diseases, and it is the most complicated kind of overflow. Hemorrhagic overflow About half of them are caused by intraductal papilloma of the breast, which is manifested by the overflow of bloody liquid from a single breast hole of one nipple, and the amount is usually relatively large. Bloody overflow should be highly suspected in postmenopausal women over 50 years old, especially if the overflow is from a single nipple. In addition, breast hyperplasia and ductal dilatation can also present with hematochezia, but less frequently. Surgery or trauma to the breast can also cause nipple overflow and should be distinguished. 3, milk-like overflow is mostly caused by benign breast diseases, such as mastoproliferative disease and ductal dilatation. In cases of amenorrhea and lactation syndrome and certain medications, there is mostly overflow from multiple breast holes in both breasts, and the amount is usually large. A large amount of overflow should also be recommended to check the serum prolactin level, if significantly elevated should be considered pituitary adenoma, can be further cranial radiography or CT examination to clarify the diagnosis. 4.Purulent overflow Purulent overflow is commonly associated with breast duct dilatation combined with infection or acute purulent mastitis. Purulent overflow has nothing to do with breast cancer, but clinical diagnosis cannot be generalized, and thorough examination should be done as much as possible. 5.clear water-like overflow is seen in intraductal papilloma, ductal dilatation and mastopathy. Clear water-like overflow has the possibility of the existence of breast cancer. 6.Multi-colored viscous overflow may be formed by the lysis of stagnant lipids, which can be seen in menopause or young women with low sexual function and ductal dilatation, and also in breast cancer and mastoproliferative disease.