Patients with mastitis have a hard lump after healing, which is considered to be a scar formed after the inflammatory reaction. If the patient has no clinical symptoms, regular follow-up and observation, avoiding external stimuli, and appropriate physical and functional exercise can be performed. In some cases, the inflammation is limited and regular ultrasound examinations can be performed. If a cystic or pus cavity is found, a segmental excision of the breast tissue can be chosen after the inflammation is limited, which can completely remove the lesion and avoid the formation of a residual cavity after surgery. Mastitis is mainly caused by improper breastfeeding practices during lactation, and is formed by secondary infection due to milk stagnation or nipple rupture. Systematic anti-infection treatment should be given during the acute phase to prevent the formation of breast abscesses. With early treatment, the inflammation can usually be limited and can be effectively cured.