The pink pus coming out of the nipple is mainly considered to be related to external injury, breast infection, breast cancer and other diseases. 1. External damage: the patient’s breast has been hit by external force, resulting in the rupture of mammary capillaries, and then the symptoms of pink pus from the nipple. 2. Breast infection: Bacterial infection or aseptic inflammation can cause mastitis and other diseases. This can lead to congestion, redness and swelling of the mammary glands, and even pus and blood secretions. 3. Breast cancer: when squeezing the nipple, it will cause some compression on the tumor, which will lead to some pus and blood secretion from the tumor, and then the symptom of pink secretion. At the same time, breast cystic hyperplasia, intraductal papilloma, breast ductal dilatation and other diseases will also appear pus, should pay attention to identify. There are many diseases that cause pink pus to come out of the nipple. When this symptom occurs, you should seek medical attention as soon as possible for a clear diagnosis and timely treatment under the guidance of your doctor.