Acute mastitis is an acute purulent infection of the mammary gland, an inflammation of the connective tissue in and around the ducts of the mammary gland, which occurs in postpartum lactating women, especially in primiparous women. It is a common occurrence in postpartum lactating women, especially in primiparous women. There are two reasons for this: milk stagnation: milk is the ideal medium for the growth and reproduction of invading bacteria, and bacterial invasion. It occurs mostly in primiparous mothers, but can also occur with weaning and after 6 months when the baby is teething, which can easily lead to nipple damage. Clinical manifestations: early swelling of the breast, local hard nodules, then redness, swelling, heat and pressure pain; formation of abscesses, there is a sense of fluctuation, superficial infection can be self-ruptured; the affected axillary lymph enlargement, pressure pain, and may be accompanied by systemic symptoms. Treatment: The principle is to eliminate the infection and drain the milk, and surgery is not advisable in early manifestations of cellulitis, but only anti-infection treatment after abscess formation may lead to more destruction of breast tissue. The main bacteria is Staphylococcus aureus, which can be treated with penicillin without waiting for the results of bacterial culture. In case of allergy to penicillin, erythromycin can be applied. If there is no significant improvement after treatment, repeated punctures should be performed to demonstrate the presence or absence of abscess formation. Important treatment can be applied externally with dandelion and cactus, especially cactus has good effect in the early stage. After abscess formation, the main treatment measure is to do abscess incision and drainage in time. Generally, breastfeeding is not stopped, which not only affects the development of infants and provides the opportunity for milk stagnation, but breastfeeding should be stopped on the affected side, and milk should be sucked out with a breast pump to promote milk elimination and local hot compresses to facilitate early inflammation absorption. If the infection is severe or the milk leaks after abscess drainage, breastfeeding should be stopped. Prevention The key is to avoid milk stagnation, prevent nipple injury, and keep the nipple clean. If there is nipple invagination, it can be corrected by frequent squeezing and lifting. It is important to develop good habits such as regular breastfeeding and babies sleeping without nipples. Each time you breastfeed, empty the milk, and if there is stagnation, massage or use a breast pump to drain the milk. Pay attention to the baby’s oral hygiene.