Gangrene: Tissue death due to loss of adequate blood supply. Sometimes bacteria invade such tissue and accelerate its decay. Dry gangrene is the death of tissue due to vascular insufficiency without bacterial invasion in which the tissue dies, loses sensation and simply dries up, blackens, and shrivels. Dry gangrene eventually requires amputation. Gas gangrene occurs when body tissue is invaded by bacteria that thrive in areas of low oxygen content. These bacteria are called anaerobic bacteria and include the Clostridium family of bacteria. The bacteria generate gas and pus; the tissues swells and can become painful. Wet gangrene requires urgent antibiotic treatment and sometimes surgical drainage.