A hard bump on the foot is painful, often in the following cases: a. Tendon sheath cyst and infection. The tendon sheath in the foot is accompanied by cyst-like hyperplastic changes due to repeated wear and tear. If it is accompanied by obvious infection, it will cause local pain symptoms. In this case, it is recommended that the patient should have the tendon sheath cyst removed as soon as possible to relieve the pain and to avoid aggravating the infection and causing serious complications. Second, sebaceous cysts with infection, which is mainly due to the pores of the foot, due to excrement blockage caused by local infection. If the infection is heavy, it will be accompanied by local pus accumulation, and patients are advised to perform abscess incision and drainage, which can control the symptoms of infection in the foot and reduce pain. After the infection of the sebaceous gland is completely controlled, complete excision of the sebaceous cyst can be considered to avoid recurrence of the lesion.