Redness and swelling around the wound after mastitis surgery is firstly considered to be caused by bacterial infection, which may also be caused by fat liquefaction at the incision after the surgery, and may also be caused by the stimulation of foreign objects inside the incision, which need to be dealt with by doctors in time. 1. Bacterial infection: Because mastitis itself is a bacterial infection, redness and swelling around the wound after surgery, considering that the bacterial infection still exists, mostly accompanied by pain, the local temperature of the affected area is higher than the normal skin, you need to give disinfection and change the medicine on time, combined with amoxicillin and other antibacterial drugs to fight infection. 2. Fat liquefaction: it is mostly due to the damage to the fat tissue at the incision during surgery, especially the excessive application of electric knife, resulting in necrosis of the fat tissue, the patient will be manifested as softening of the incision, oozing, etc., and redness and swelling may also appear when accompanied by bacterial infection. 2. Foreign body reaction: after surgery, if there is a foreign body in the wound, or the patient who sewed the wound has a rejection reaction to the wound suture, there may also be redness and swelling of the wound, and it is necessary to remove the suture in time or switch to absorbable thread to re-suture the wound. The specific situation is recommended to go to the hospital for examination by a professional physician according to the patient’s condition to give the appropriate treatment, there are side effects and contraindications to the drug, so you need to use under the guidance of a professional physician.