Corns and callouses are a buildup of thickened skin in response to pressure – in the same way you may develop callouses on your hands from constant pressure from hand tools.
When the buildup of skin is diffuse or spread out, it is called a callous.
When the buildup of skin is very dense and hard, it is called a corn.
As the skin becomes thicker, it can become painful. It is the skin itself that adds to the pressure on the area involved.
The treatment will depend on the reason you are having the pressure in that area.
Initially, cushioning or padding the area helps. In addition, applying a moisturizing cream helps to reduce friction and pressure on the area.
As the problem progresses, a visit to the podiatrist may be required to reduce the thickening of skin to provide temporary relief, however the problem usually returns.
The podiatrist will evaluate the underlying cause the of pressure on the area and may recommend conservative care such as a custom molded insert called an orthotic to reduce abnormal pressures. Occasionally, more involved treatment, such as surgery, is required.