Calluses on the palms of the feet, known as calluses, can be caused by ill-fitting shoes or by foot deformities. When the skin is pressed and rubbed for a long period of time, a hard and smooth thickening of the corns, i.e. callus, will occur. Long-term wearing of ill-fitting feet, wearing high heels for a long time, wearing shoes without socks, and standing or walking for long periods of time can all lead to calluses in the feet. When there are deformities in the feet, such as clubfoot, hammer toes, and bone spurs in the feet, they can also lead to calluses. Foot calluses caused by excessive friction require proper footwear and insoles of appropriate thickness to minimize friction. For calluses caused by foot deformities, surgery is recommended to correct the alignment of the bones that cause friction or to give special orthotic insoles.