Mastitis during breastfeeding can manifest as redness, swelling and pain in the breast. If the nipples are cracked during breastfeeding, bacteria invade from the nipples or some women have a strong milk production, but the baby’s milk is small, forming milk stagnation and blockage of the milk ducts, thus easily causing mastitis, the mother can have breast swelling and pain, which can also generally manifest as an elevated body temperature, blood tests can indicate elevated blood picture, such as elevated white blood cells or neutrophils, and the breasts are seen to be red, swollen and hot, even untouchable, if suspected If mastitis is suspected, it is recommended to go to the hospital for timely consultation. If mastitis is diagnosed, antibiotics should be given orally or by drip anti-infection treatment in a timely manner to avoid causing pus, and if an abscess is formed an incision and drainage is needed. For postpartum women, it is important to maintain a good state of mind and prevent emotional depression. For babies who do not suck much but have sore breasts, it is recommended to empty the milk in time, keep the breasts clean and hygienic, wash the breasts with warm water often to prevent breast cracking, which are all unfavorable factors that can easily lead to mastitis during breastfeeding and should be avoided as much as possible. In conclusion, mastitis during breastfeeding can manifest itself as redness, swelling, heat and pain in the breast. It is recommended to seek medical attention in a timely manner to avoid aggravation of the condition and to suspend breastfeeding if antibiotic treatment is administered.