What is a corn on the foot?

A corn on the foot is an area of thickened skin with a hard center, according to WebMD. Soft corns have a thinner surface than hard corns.

Most corns develop between the toes and on the tops and sides of the feet, but they can occur on the bottom of the foot as well, notes WebMD. Corns often develop due to friction or pressure on the foot, explains Mayo Clinic. Wearing footwear that doesn't fit properly is frequently the origin of the friction or pressure. Tight shoes press and rub on certain spots, causing corns, while loose shoes allow the foot to slide around, resulting in rubbing and irritation. Not wearing socks with shoes can also contribute to the friction that often causes corns.