A corn, also known as a clavus, is a type of thickened and hardened skin that typically develops on the feet, particularly on the top or sides of the toes or on the soles. Corns are generally small, round or cone-shaped, and have a central core that can be tender or painful when pressure is applied.

Corns are usually caused by repetitive friction or pressure on the skin, often due to ill-fitting footwear or excessive rubbing against a bony prominence. The body responds to this pressure by producing layers of dead skin cells, resulting in the formation of a corn.

There are two main types of corns:

Hard Corns (Heloma Durum): These are the most common type of corns. Hard corns are characterized by a dense, thickened center and are typically found on the tops or sides of the toes. They may appear yellowish or gray and can be painful when pressed.

Soft Corns (Heloma Molle): Soft corns are less common but can be more painful than hard corns. They usually develop between the toes, where the skin is moist and prone to friction. Soft corns have a rubbery texture and are often white and macerated.

In addition to footwear that causes friction, factors that can contribute to the development of corns include foot deformities, such as bunions or hammer toes, high foot arches, excessive sweating, and certain activities that put pressure on the feet.