A foot ulcer is an open sore on the foot. It can appear as a shallow red crater that involves only the surface skin, or it can be very deep. A deep foot ulcer may extend through the full thickness of the skin, and can involve tendons, bones and other deep structures.

People with diabetes and/or poor circulation are more likely to develop foot ulcers, which can become infected if it is not given prompt and proper attention. An infected ulcer can develop into a number of serious conditions, including:

  • An abscess (a pocket of pus)
  • A bone infection (osteomyelitis)
  • Gangrene – an area of dead, darkened body tissue caused by poor blood flow.


There are four major causes of foot ulcers:

  • Neuropathic— related to the nerves. There is usually a loss of feeling in these cases.
  • Arterial— a result of poor blood circulation.
  • Venous—related to poorly functioning veins.  
  • Decubitus—  excessive and prolonged pressure on one area of the foot.  


Most foot ulcers are located on the side or bottom of the foot or on the top or tip of a toe, and are often surrounded by a border of thickened, callused skin. In very severe ulcers, tendons or bones may be exposed. If the nerves in the foot are functioning normally, then the ulcer will be painful. If not, then the person may not know it is there, particularly if the ulcer is located on a less obvious portion of the foot.


Many ulcers can be treated with a procedure called debridement, which consists of trimming away diseased tissue.  Afterwards, the patient may need to wear a shoe or sandal that can be worn over a bandage, or even a cast. Dressings must be changed frequently, and if there is a possibility of infection, antibiotics may be prescribed.Foot ulcers that do not respond to more conservative therapy may require surgery.  


People who are at risk of foot ulcers, such as those with diabetes, can take steps to help prevent foot ulcers. They can do this by examining their feet routinely and following good foot-hygiene practices. The following strategies may help prevent foot ulcers:

  • Examine every part of your feet every day to check for rubbed areas, cracks or calluses.
  • Practice good foot hygiene. Wash your feet every day using mild soap and warm water. Dry thoroughly, especially between the toes.  
  • Wear shoes that fit well and soft, absorbent socks. Change socks immediately if they become wet or sweaty.
  • Trim your toenails straight across with a nail clipper or emery board.
  • If you have corns or calluses, ask your doctor about how to care for them.