Friction causes the thick, hardened, dead skin of corns and calluses, which form to protect sensitive skin. Appearing cone–shaped, corns point into the skin, and usually occur on areas that bear little weight. Calluses may appear anywhere there's friction, and are more diffuse. Both may be caused by ill–fitting shoes and will fade when friction stops. Moleskin pads can help relieve a corn; calluses can be trimmed or surgically corrected.