The appearance of redness and swelling of the inner thigh is common in the following three categories of diseases: the first major category, mainly seen in the body surface sebaceous cysts with infection, manifested as local lumps, with redness, swelling, heat and pain, and in serious cases, even the formation of abscesses, treatment mainly using antibiotics, abscess formation requires timely incision and drainage of pus treatment. The second major category, mainly seen in the lower extremity lymphangioretinitis caused by bacterial infection secondary to skin rupture of the lower extremity, is treated with antibiotics for sensitive bacteria, mainly Streptococcus haemolyticus, which is treated with sensitive antibiotics, mainly penicillin G. The third major category, a relatively rare disease, is seen in a very small number of inguinal hernia intussusception, which causes intestinal necrosis and spreads to subcutaneous cellulitis, requiring emergency surgery. For intestinal necrosis, prompt intestinal canal resection with abdominal drainage is required.