Calluses are areas of thickened hard skin that develop when the skin is exposed to excessive pressure or friction. They usually appear on the soles of the feet (around the heel or the ball of the foot). Not only are they unsightly but they can cause pain and discomfort when walking. 

 

Callus may develop in response to wearing high heels, badly fitting shoes or doing lots of walking or running. The build up of hard skin becomes more common with age due to drying skin and diminished fatty padding. The dry, hard skin may crack and provide a point of entry for bacteria.