Foot Ulcer
A foot ulcer is an open sore on the foot.
A foot ulcer can be a shallow red crater that involves only the surface skin. A foot ulcer also can be very deep. A deep foot ulcer may be a crater that extends through the full thickness of the skin. It may involve tendons, bones and other deep structures.
People with diabetes and people with poor circulation are more likely to develop foot ulcers. It can be difficult to heal a foot ulcer. In people with these conditions, even a small foot ulcer can become infected if it does not heal quickly.
If an infection occurs in an ulcer and is not treated right away, it can develop into:
An abscess (a pocket of pus)
A spreading infection of the skin and underlying fat (cellulitis)
A bone infection (osteomyelitis)
Gangrene. Gangrene is an area of dead, darkened body tissue caused by poor blood flow.
Among people with diabetes, most severe foot infections that ultimately require some part of the toe, foot or lower leg to be amputated start as a foot ulcer.