Dead or necrotic tissue. Gangrene develops when the blood supply to an affected part is cut off because of various factors including infection, vascular disease or trauma. Can involve any body part, but the commonest sites are the extremities. Can be most dangerous when gangrene affects the intestines or stomach. Wet gangrene - with bacterial infection.
Gas gangrene is a form of wet gangrene.
Trauma caused by accident or surgery or crash injury. Blood clot in an artery. Hardening of arteries. This feels like pressing on air bubbles under the skin. Foul smelling discharge from ulcers in dead tissues.