A small piece of the sole of the foot is suddenly swollen, and the common clinical causes are mainly as follows. First, the patient in strenuous exercise can cause the sole of the foot muscle strain, and accompanied by the formation of local hematoma. At this time will be accompanied by the protrusion of the lump, the patient will appear obvious pressure and pain symptoms, you can reduce the tissue exudation through local ice packs. 24 hours later, the use of hot omelette external application, blood circulation and blood stasis cream external application, oral pain and other drugs, to promote the self-absorption of the local lumps to reduce the symptoms of pain. Second, patients with epidermoid cysts on the soles of the feet with infection. This is due to repeated friction on the soles of the patient’s feet, accompanied by bacterial proliferation and acute inflammatory changes. You can apply 0.5% vitality iodine or Jin Huang San ointment topically to promote the absorption of the mass. If accompanied by abscess formation, it is necessary to carry out abscess incision and drainage, and strengthen anti-infection treatment, which can promote the early absorption of small lumps on the soles of the feet.