DefinitionGangrene is the death of tissue in part of the body.Causes, incidence, and risk factorsGangrene happens when a body part loses its blood supply. This may happen from injury, an infection, or other causes. You have a higher risk for gangrene if you have:A serious injuryBlood vessel disease (such as arteriosclerosis, also called hardening of the arteries, in your arms or legs)DiabetesSuppressed immune system (for example, from HIV or chemotherapy)SurgerySymptomsThe symptoms depend on the location and cause of the gangrene. If the skin is involved, or the gangrene is close to the skin, the symptoms may include:Discoloration (blue or black if skin is affected; red or bronze if the affected area is beneath the skin)Foul-smelling dischargeLoss of feeling in the area (which may happen a