Gangrene is the death of tissue in part of the body.

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

Gangrene requires urgent evaluation and treatment. In general, dead tissue should be removed to allow healing and prevent further infection. Depending on the area affected, the condition of the patient, and the cause of the gangrene, treatment may include:

• An emergency operation to explore or remove dead tissue
• Amputating the affected body part
• Repeated operations to remove dead tissue (debridement)
• An operation to improve blood supply to the area
• Antibiotics
• Treatment in the intensive care unit (for severely ill patients)

The outlook depends on the body part affected, the extent of gangrene, its cause, and the condition of the patient. The patient may die if treatment is delayed, the affected area is extensive, or the patient has other significant medical conditions.

Complications depend on the body part affected, the extent of gangrene, its cause, and the condition of the patient. Complications may include:

• Disability from amputation or removal of dead tissue
• Prolonged wound healing or the need for reconstructive surgery, such as skin grafting

Call your doctor immediately if:

• An area of your skin turns blue or black
• You have persistent, unexplained pain in an area
• You have persistent, unexplained fever
• A wound does not heal or there are frequent sores in an area
• There is foul-smelling discharge

Gangrene may be prevented if a harmful process is treated before the tissue damage is irreversible. Wounds should be treated properly and observed for signs of infection (such as spreading redness, swelling, or drainage) or failure to heal. Patients with diabetes or blood vessel disease should routinely examine their feet for any signs of injury, infection, or change in skin color and seek care as needed.