Corns and calluses are thickened layers of skin caused by repeated pressure or friction.Corns and calluses are annoying and sometimes painful thickenings that form in the skin in areas of pressure. The medical term for the thickened skin that forms corns and calluses is hyperkeratosis. A callus refers to a more diffuse, flattened area of thick skin, while a corn is a thick, localized area that usually has a conical or circular shape. Corns, also known as helomas, sometimes have a dry, waxy, or translucent appearance.

Corns and calluses occur on parts of the feet and sometimes the fingers. Corns can be painful to walk on, even when they are small.Hyperkeratosis simply means thickening of the skin; this thickening occurs as a natural defense mechanism that strengthens the skin in areas of friction or pressure. Abnormal anatomy of the feet, such as hammer toe or other toe deformities,can lead to corn.