Pain on the inside of the big toe is commonly caused by the following: first, bunion, inversion of the first metatarsal, bunion deformity, causing local pain, is a common foot deformity, etiology, including shoes too narrow, too pointed or long-term wearing of high-heeled shoes, resulting in forefoot, especially bunion deformity, the first metatarsal is too long and other factors, clinical manifestations of the first metatarsophalangeal joint to the medial projection, pain when walking, local callus, bunion pressure on the second toe, the second toe is often accompanied by mallet fingers, pain in the first metatarsophalangeal joint when bearing weight, radiographs show osteophytes near the first metatarsophalangeal joint and subluxation or dislocation of the first metatarsophalangeal joint in addition to bunion. Second, bunions, long-term repeated friction between the shoe and the inner side of the bunion, producing inflammation of the bunion, manifested as local pain symptoms.