A callus is a thickened pad of skin, usually on the weight-bearing portion of the sole, that results from chafing and pressure.

A corn is a highly concentrated callus that occurs at a pressure point, such as the top of the toe or under a toe joint.

Either can be painful when they press on sensitive nerves in the surrounding skin, which may become red and inflamed.

Corns are small, rough mounds of firm, dead skin that form on or between the toes. Their hard, waxy core, which bores down into the...