Gangrene
Dry gangrene is usually caused by a loss of blood supply to the affected area, such as may happen following an injury which damages the blood vessels to the affected area. Wet gangrene usually occurs when a wound becomes infected with various types of bacteria. Gas gangrene is usually  caused by clostridium bacteria and mainly affects the muscles. Internal gangrene affects the internal organs, usually the intestines, gallbladder, or appendix.