If the blood overflow from the breast gets better again in a few days, it refers to nipple blood overflow, which may be related to acute mastitis, papilloma in the milk ducts, and breast cancer. 1. Acute mastitis: It may be related to long-term milk stagnation and bacterial infection. Patients with acute mastitis will have a lump in the breast, which is as hard as a stone in severe cases, and is accompanied by obvious tingling sensation, nipple milk spillage, and localized skin warmth, etc. If the symptoms are more serious, there may be a generalized fever. If the symptoms are more serious, there may be generalized fever, nipple blood overflow and other phenomena. 2. Intraductal papilloma: Due to the presence of tumor, it will lead to space-occupying lesions in the space inside the breast ducts, causing nipple bleeding and other phenomena, and accompanied by pain. 3. Breast cancer: the most typical symptoms of breast cancer are nipple bleeding and breast lumps. If breast cancer aggravates, patients will also have symptoms such as orange peel skin changes. It is recommended that the patient should seek medical advice in time and under the guidance of the doctor to carry out systematic examination to clarify the causes of the disease.