Lactational mastitis is an acute purulent infection of the mammary gland during lactation. Most of the patients are primigravid women, and most of them develop about three weeks after delivery. The main symptoms are redness, swelling, heat and pain in the breast, as well as the formation of localized lumps and abscesses, and elevated body temperature, etc. The cause of lactational mastitis is that the baby’s nipple can be broken by bacteria during breastfeeding. The main reason for breastfeeding mastitis is that the baby holds the nipple in his mouth for a long time during breastfeeding, and bacteria can enter through the broken nipple and invade along the lymph ducts to cause infection. The second reason is that the milk is not drained in time, resulting in stagnation and bacterial invasion and growth. Breastfeeding mastitis can lead to breast cancer if not detected and treated in time, so special attention must be paid to it. Especially if you are a new mother with no breastfeeding experience, you should pay special attention to prevention. During breastfeeding, you should pay attention to keeping your nipples clean and not letting your baby sleep with your nipples. Once related symptoms appear, you should go to the hospital for breast examination and early treatment to avoid delay. Breastfeeding mothers must pay attention to rest, eat more fruits and vegetables to replenish the body’s nutrients, enhance immunity and reduce the occurrence of various diseases.