Corns are thick, hardened layers of skin that develop when the skin tries to protect itself against friction or pressure. They can be small and round, and tend to develop on the tops and sides of toes. Calluses, on the other hand, are hard, thick patches of skin that can vary in size and shape and are usually found on the bottom of the feet on the bony areas that carry your weight. They are essentially the same tissue as corns. Corns and calluses can be caused by poorly-fitting shoes, bone pressure against the skin, or repeated friction. If youre healthy, you don't need treatment for corns and calluses unless they cause pain or you don't like how they look. For most people, simply removing the source of the friction or pressure makes corns and calluses disappear. To treat corns and calluses, dermatologists recommend soaking and filing the feet and using a moisturizer. Over-the-counter products are also available.