Etiology】The occurrence of corns is related to the long-term mechanical friction or pressure on the foot, the local qi and blood does not run smoothly, the skin is not nourished, local keratin hyperplasia, and cone-shaped embedded in the dermis, that is, the formation of corns. Most often occur in tight shoes and boots, long-term walking or foot deformity or elderly people with poor tissue repair ability. Clinical manifestations] Due to long-term local skin extrusion and friction caused by significant hyperplasia of the keratin layer, and cone-shaped, embedded in the dermis, the tip of the protrusion into the dermis, compression of nerve endings, once the local pressure or extrusion will cause obvious pain. The skin surface is a round or oval, yellowish, hard spot with clear boundaries, generally the size of a soybean, with tenderness. The actual fact is that you can find a lot of people who have been in the business for a long time. (3) cryotherapy, simple, convenient, less damage, easy care, basically does not affect the work. Our department mostly uses cryotherapy. Prevention】Cocksores are generally not easy to heal on their own, after treatment, but also pay attention to prevent recurrence, to treat your feet. (1) wear loose, suitable size and soft shoes, or small sponge pads with holes to protect the local to avoid pressure; (2) after exercise more hot water soak feet to increase its blood circulation.