Nipple overflow refers to the phenomenon of abnormal nipple overflow during the non-lactation period. According to the nature of nipple overflow can be divided into: 1, white nipple overflow: suffering from increased lactogen, pituitary lesions pituitary tumor, and stop breastfeeding after the retention of milk can appear white overflow; 2, yellowish plasma nipple overflow: the occurrence of breast hyperplasia, flat epithelium will become a single layer of columnar epithelium, resulting in columnar epithelium has a secretory function; 3, bloody nipple overflow: bloody nipple overflow and divided into two cases, bright red Blood, dark brown blood, these two conditions appear to be highly important. Breast cancer, intraductal papilloma, and benign tumors can all have bloody nipple discharge.