Gangrene can occur when a body part loses its blood supply. This may happen from, for example, injury or infection. You have a higher risk for gangrene if you have:

• Diabetes
• Blood vessel disease (such as arteriosclerosis in your arms or legs)
• A serious injury
• Surgery
• Immunosuppression (for example, from HIV or chemotherapy)

The symptoms depend on the location and cause of the gangrene. If the affected area involves the skin or is close to the skin, the symptoms may include:

• Discoloration (blue or black if skin is affected; red or bronze if the affected area is beneath the skin)
• Loss of sensation (which may occur after severe pain in the area)
• Foul-smelling discharge

If the affected area is internal (such as gangrene of the gallbladder or gas gangrene), the symptoms may include:

• Persistent or severe pain
• Fever
• Gas in tissues beneath the skin
• General ill feeling
• Septic shock

The doctor may diagnose gangrene from a physical examination. In addition, the following tests and procedures may be performed to diagnose gangrene:

• Blood tests -- a CBC may show a high white blood cell (WBC) count
• X-rays
• CT scan for internal conditions, such as abdominal pain
• Surgical exploration to confirm (and treat) gangrene
• Microscopic examination of tissue to look for cell death
• Tissue or fluid culture from wounds to identify bacterial infection
• An arteriogram to help plan treatment for vascular disease