A corn on the foot is a small, thickened area of skin that develops on the top or side of a toe. It is a type of callus made of dead skin that forms in response to pressure or friction. Corns can be hard and dry or soft and mushy, and they can be painful when pressed. They are usually caused by ill-fitting shoes, but they can also develop due to bone pressure against the skin. Corns and calluses are not the same thing, although they are often used interchangeably. Corns are smaller and deeper than calluses and have a hard center surrounded by swollen skin. If a corn causes pain or discomfort, it can be treated by removing the source of friction or pressure, such as changing to shoes with a better fit, and protecting the corn with a doughnut-shaped corn pad while it is healing. Over-the-counter products used to dissolve corns and calluses contain harsh chemicals, so it is important to be precise in applying the chemical to avoid injuring the surrounding healthy skin. If a corn or callus becomes very painful or inflamed, or if the person has diabetes, fragile skin, or circulatory problems, it is important to seek medical care.