Gangrene is the progressive death of body tissue resulting from a lack of blood supply. When the blood supply is cut off, the tissue does not get enough oxygen and begins to die.

Gangrene can be internal or external. The two most common types of gangrene are:

  • Dry gangrene—Lack of blood supply causes the tissue to die.
  • Wet gangrene—Usually occurs when the tissue is infected with bacteria from an injury. The tissue becomes moist and breaks down.

A rare wet type, called gas gangrene, develops from specific bacteria deep inside the body. Gas gangrene can be a result of surgery or trauma.

Gangrene is caused by infection or a reduced blood supply to tissues.