The clinical manifestations of mastitis can be divided into three phases or stages. The first stage is the bruised milk lump stage or erythema stage, which is mainly characterized by a sudden swelling, hardness, distension and pain in a part of the breast, usually the upper outer or upper inner quadrant, with unclear borders and obvious tenderness. In this stage, the inflammation within the breast is in the cellulitis stage and no abscess has formed. The color of breast skin is normal or slightly red or slightly hot, with sudden high fever and chills, pain and swelling, local bright red, pus breaks out, mostly accompanied by chest tightness, headache, loss of appetite and so on. If there is nipple rupture, when breastfeeding, you will feel the nipple like pins and needles pain, the surface of the nipple can be seen 1-2 small pus spots, or very small cracks. The second stage is the abscess formation stage, the cellulitis stage fails to dissipate in time, the inflammation continues to develop, tissue necrosis, abscess formation is inevitable, the lump gradually becomes larger, harder, the pain worsens, mostly throbbing throbbing pain, or even persistent severe pain, localized redness of the skin of the breast, burning heat, the whole body is strong and unrelenting heat, thirst and desire to drink, nausea, anorexia, ipsilateral axillary lymph node enlargement and so on, redness, swelling, heat and pain, and after 2-3 days, the After 2-3 days, the central part of the lump gradually becomes soft, with pulsating sensation, the center of the redness and swelling is bright, the skin becomes thin, the surrounding skin is large and bright red, and the pus will be sucked out by puncture, at this time, the abscess has been formed, and the time for conservative treatment has passed. The third stage is the period of abscess ulceration, the abscess can be broken by itself after maturity, or surgical incision and drainage of pus. If the drainage is smooth, the local swelling and pain will be reduced.