Gangrene is death or damage of body tissue due to a loss of blood supply. Gangrene may be caused by reduced blood flow in the arteries, or it can result from a severe bacterial infection. Gangrene may affect any part of the body. One form of this condition, called Fournier's gangrene, affects the male genitalia. Gangrene is a medical emergency. Some types of infectious gangrene are life-threatening. Follow the links below to find WebMD's comprehensive coverage bout how gangrene develops, what it looks like, how to treat it, and much more.