Gangrene

Gangrene is a medical emergency in which blood stops flowing to a specific part of your body, and tissues in that area die. Gangrene can develop anywhere in your body, but it often starts in your foot or hand.

Gangrene always involves tissue death, but it doesn’t always involve an infection. A gangrene infection is when bacteria grow in the affected area. Without prompt treatment, gangrene (with or without an infection) can lead to serious complications or death.

Types of gangrene

There are several types of gangrene:

• Dry gangrene. This is when blood can’t reach a certain area of your body, but there’s no infection. Your skin will feel dry to the touch (no open blisters or pus). Plaque buildup in your arteries (atherosclerosis) is commonly responsible for dry gangrene.
• Wet gangrene. This is disrupted blood flow along with a bacterial infection. Blisters that release pus (the “wet” factor) form on your skin. Wet gangrene spreads quickly to nearby tissues.
• Gas gangrene. This bacterial infection destroys your soft tissues and blood cells. Bacteria quickly multiply in your muscle tissue, forming toxins and releasing gas. The infection spreads fast and can become life-threatening within hours of symptom onset.
• Fournier’s gangrene. This is a rare, severe bacterial infection that affects your genital area. It affects males more often than females.
• Internal gangrene. This is blocked blood flow to internal organs. Affected organs many include your gallbladder, intestines or appendix. A gangrenous gallbladder is a serious complication of chronic cholecystitis, where continued swelling leads to tissue death.

Symptoms of gangrene

Gangrene symptoms vary by type and may include:

• Changes in skin color (red, purple, green or black)
• Changes in how your skin feels (pale, firm, cool and/or tender to the touch)
• Crackling sound when you press on your skin (this means there’s a gas buildup underneath)
• Fast breathing and heart rate
• Feeling very anxious
• Flu-like symptoms like fever, sweating, chills and vomiting
• Severe pain or a loss of feeling
• Sores and blisters that release blood or foul-smelling pus
• Swelling of the affected area

What does gangrene look like?

Gangrene causes skin color changes that may occur in stages:

1. At first, your skin may look paler than usual due to lack of blood flow.
2. Then, it turns red or reddish in color.
3. It may then turn brown before changing to purple or greenish-black.

It may be more difficult to see these color changes if you have a darker skin tone.

If there’s an infection, you’ll notice sores or blisters with smelly fluid coming out.

Gangrene causes

Lack of blood flow to a specific part of your body causes gangrene. Blood delivers oxygen, nutrients and antibodies to your tissues. When your tissues don’t receive blood, they start to die.

Causes of blocked blood flow include:

• Medical conditions, like peripheral artery disease, that affect your circulation
• Deep wounds
• Surgical complications (rare)

Risk factors

You face an increased risk of gangrene if you have a condition that affects your blood vessels. Examples include:

• Buerger’s disease. Inflammation of blood vessels in your limbs leads to blood clots that block blood flow.
• Diabetes. This condition damages your nerves and blood vessels. It also causes wounds to heal more slowly. Slow-healing wounds face a higher risk of infection.
• Peripheral artery disease. Plaque buildup in your arteries prevents enough blood from reaching your legs, feet, arms or hands. This is the most common cause of dry gangrene.
• Popliteal artery entrapment syndrome. Your calf muscle squeezes your popliteal artery. This limits blood flow to your lower leg during exercise.
• Raynaud’s syndrome. Cold temperatures affect the blood vessels in your fingers and toes. Your blood vessels narrow, limiting blood flow.
• Vasculitis. Inflammation of your blood vessels interferes with blood flow.

You also face a higher risk of gangrene if you have:

• A traumatic injury
• A weakened immune system
• Severe tissue damage from frostbite or burns

If you have any risk factors, see your provider for regular checkups and keep all your follow-up appointments. Your provider will tell you what you can do at home to lower your risk of gangrene — like taking good care of your feet and tending to wounds.

Some medications have been associated with an increased risk of Fournier’s gangrene. Your provider should counsel you on this before starting the medications.

Complications of gangrene

Gangrene is serious and can be life-threatening. It may lead to:

• Loss of a body part, like a finger, toe, hand or foot
• Sepsis
• Organ failure

Gangrene is sometimes fatal.

How doctors diagnose this condition

See a healthcare provider right away if you think you have gangrene. Your provider will:

• Ask you about your medical history and current conditions
• Ask you about any recent injuries
• Carefully evaluate the affected area of your body
• Run tests to learn more

Tests you may need include:

• Blood tests
• Bacterial culture tests
• Imaging tests, like X-rays, CT scans and MRIs
• Tests that check blood flow, like an ankle-brachial index

These tests help your provider learn:

• What’s blocking blood flow
• Whether or not there’s an infection
• How much tissue is damaged
• What the best treatment options will be

How is gangrene treated?

Gangrene treatments aim to stop gangrene from spreading, remove dead tissue and help blood flow better. You may need one or more treatments, including:

• Antibiotics. When a bacterial infection causes gangrene, you need antibiotics. Your provider will prescribe the proper dosage for you.
• Debridement. This is the medical term for dead tissue removal. Gangrenous (dead) tissue doesn’t heal, and the only option is to remove these tissues. Doing so protects nearby healthy areas and helps damaged (but not dead) tissues heal. 
• Procedures to improve blood flow. Your provider may perform a procedure to widen your arteries (angioplasty) or create a new path for blood to flow around the blockage (bypass surgery).
• Hyperbaric oxygen therapy (HBOT). HBOT sends high levels of oxygen through your body’s tissues, helping to heal them.
• Amputation. This is the removal of the affected body part, like a toe, foot, hand or finger. Providers only use amputation if other treatments won’t do enough to save healthy tissues (or your life).

After gangrene treatment, you may choose to have skin graft surgery. A provider uses healthy skin from another part of your body to cover scars or damaged skin.

When should I seek medical care?

Call 911 (or your local emergency service number) or go to your local emergency room if you have gangrene symptoms. You should also seek emergency help if you have symptoms of septic shock:

• Fast but weak pulse
• Feeling confused or disoriented
• Feeling dizzy when you stand up
• Skin that’s cold, clammy and pale
• Trouble breathing
• Vomiting or diarrhea

What is the life expectancy for people with gangrene?

What you can expect, including your life expectancy, depends on many factors, including:

• How much the gangrene has spread
• How soon you receive treatment
• Which parts of your body are affected
• Your overall health

Your healthcare provider knows your situation best and can give you the most accurate prognosis.

Without treatment, gangrene can quickly become fatal. How long it takes for gangrene to cause death depends on the type of gangrene you have. Gas gangrene progresses very fast. The area of dead tissue can expand several inches with every hour that passes. Gas gangrene is always fatal without treatment, and sometimes fatal even with treatment.

For any type of gangrene, the sooner you get treatment, the better your chances of survival.

Is gangrene contagious?

Gangrene itself isn’t contagious. That means gangrene doesn’t spread from person to person. But it may be possible for the bacteria that cause a gangrene infection to spread to others. How the bacteria affect an exposed individual depends on many things, like whether they have an open wound at the site of contact and their overall health status.

Talk to a healthcare provider if you or someone in your household has a gangrene infection. They’ll let you know if there are any precautions you should take.