How long does it take for gangrene to kill you?

Gangrene (decomposition and infection) does not occur until after a certain amount of cell death (necrosis) in living tissue. Aside from direct contamination with disease organisms (gas gangrene), gangrene seldom appears sooner than 48 to 72 hours after necrotic onset, depending on the temperature and tissue condition. Because the dead tissues spread infection to adjacent cells, removing them is the primary treatment, as well as applying antibiotics to limit bacterial growth.