Gangrene
Gangrene, mass death or necrosis of individual cells or tissues of a living organism. The immediate physiological cause of gangrene is blockage of arterial blood supply. Among the symptoms of gangrene are loss of sensation and function. The affected part, usually a limb, becomes cold, turns progressively darker in color, and finally undergoes decomposition. Gangrene may take two forms, dry gangrene or moist gangrene. Dry, or chronic, gangrene occurs when the arteries are blocked gradually and the tissues are bloodless. It may be a result of arteriosclerosis (see Artery). It may also follow frostbite, injury, or the vascular collapse that often accompanies diabetes. If the dead, bloodless tissue becomes infected by the anaerobic bacterium Clostridium, the condition is called moist, or acute, gangrene. It is also known as gas gangrene because of its putrid-smelling gaseous discharge. The victim's temperature rises sharply, and he or she suffers great pain, acute anemia , and prostr