There are many reasons for nipple redness and swelling, which need to be treated symptomatically for the cause, such as the application of penicillin and other antibiotics, hot compresses and so on. 1. Inflammation of the mammary glands: Mastitis is caused by an acute infection of the breasts, and is more common in new mothers, because new mothers have milk stagnation, which is caused by secondary infections. After the skin of the nipple breaks down, it will lead to bacterial invasion and infection, causing redness, swelling and pain in the nipple of the breast. Generally take antibiotics to deal with, such as penicillin. 2. Mammary gland hyperplasia: it may be related to endocrine disorders, which will lead to nipple redness, swelling, pain, pain shows cyclical changes, regularity, pain symptoms will be aggravated before the onset of menstruation, and the symptoms can be relieved after menstruation. You can mainly use hot towels to promote local blood circulation to relieve the pain. 3. Breast malignant tumor: red and swollen nipples may be related to certain breast malignant tumor diseases, you can go to the hospital for relevant examinations, if considered as breast cancer, should receive comprehensive treatment mainly based on surgical treatment. There are many reasons for nipple redness and swelling, we suggest that patients go to regular hospitals in time to find out the cause of the problem and follow the doctor’s instructions to receive treatment.