Corns and Calluses are patches of hard, thickened skin found on the foot, formed in response to pressure or friction. A Callus is typically found on the bottom of the foot and is caused by a combination of shear and twisting forces when walking. The skin thickens with callus to add protection from these forces.
A Corn is caused by a more direct source of pressure. It is smaller in size but often goes deeper, causing the corn to be particularly painful. People at high risk of corns and calluses include the elderly, anyone who stands on their feet for long periods of time, people with flat feet, and people who wear ill-fitting footwear.