A Callus on the foot is an remarkably toughened area of skin, which has become thickened and hard as a response to repeated contact or pressure. Since repeated contact is what causes the callus, calluses are most often found on feet. Calluses are in general not detrimental but can sometimes lead to other foot problems, such as an infection. Tight fitting shoes can often make calluses on the feet.
When a Callus develops a mass of dead cells in its center, it becomes a corn (heloma). Corns commonly occur on the toes and balls of the feet. Calluses occur on the feet, hands, and any other part of the skin where friction is present.