Corns and calluses can develop when the affected area of the foot is exposed to excessive pressure or friction.

Corns

Corns are often caused by pressure on the foot from poorly fitting shoes.

High-heeled shoes can squeeze the toes, and shoes that are too loose can allow your foot to slide and rub.

Corns often develop on the little toe, which tends to rub against the end of the shoe.

People who have misshapen feet or prominent bones in their feet are susceptible to corns.

Calluses

When you walk or stand, your body weight is carried first on the heel and then on the ball of your foot. When the pressure in one of these areas becomes excessive, the skin thickens to protect the underlying tissue and calluses may develop.

Activities that put repeated pressure on the foot, such as running or walking barefoot, can cause calluses to form. Athletes are particularly susceptible to them.

Some people develop calluses as a result of their skin type. Elderly people have less fatty tissue in their skin, which means less padding. This can cause a callus to form on the ball of the foot.

As with corns, calluses are sometimes an indication of a bone deformity, such as a bunion (a bony swelling at the base of the toe).

As well as forming on the feet, calluses can also sometimes develop on the palms of the hands from holding an object such as a racquet or hammer. They can also develop on the knuckle pads if you regularly have to push yourself out of a wheelchair.