Inflammation of the breast, also known as mastitis, occurs mostly in breastfeeding women and is mostly a bacterial infection caused by poor milk drainage. The symptom is breast pain, most of the pain is relatively clear fixed pressure pain will increase, some breast skin will have redness and swelling, if serious cases will also have a rise in body temperature, fever, and even the formation of breast abscesses. The treatment of mastitis; first, the milk should be emptied in time, you can let the baby suck more times or use a breast pump to suck out the milk, because the milk is a better medium for bacteria, can promote the proliferation of bacteria. Secondly, hot towels and then light massage. Third, if not relieved, you can take oral antibiotics, such as cefaclor, because this drug has less impact on breastfeeding. Fourth, if the pain is getting heavier, the mass is getting bigger and bigger, and even the temperature starts to fever, think about the possibility of breast abscess, you can do ultrasound to clarify, if it is an abscess need to be promptly incised and drained.