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What is gangrene?

Gangrene is a serious, life-threatening condition that affects the body’s tissues. Most commonly, gangrene affects the skin, although any part of the body can become gangrenous. Tissue cells need good blood flow that provides them with oxygen and other nutrients to thrive. Any interruption to that flow can cause the cells to die, resulting in gangrene.

Gangrene can be caused by a vascular problem that stops the blood flow (dry gangrene), or other causes, like bacterial infections and sepsis (wet gangrene). To treat gangrene successfully, doctors must work quickly to either restore the blood flow to the affected area, or to remove the gangrenous tissue so it does not spread.

Anyone can develop gangrene, but people with chronic health conditions that affect the blood circulation are at higher risk for gangrene. This includes people who have diabetes or peripheral artery disease, for instance.

Gangrene can be a life-threatening condition if it is not treated early and quickly enough. Seek emergency care (call 911) if you or someone you are with has symptoms of gangrene, including discoloration of skin, pain, swelling, coldness to the touch, pus or discharge, fever, or severe internal pain.

What are the different types of gangrene?

There are several types of gangrene:

  • Dry gangrene: Dry gangrene occurs if the blood supply to body tissue is cut off. This could be gradual, as the tissue slowly loses its blood supply. It can also occur faster, perhaps the result of an accident, being stuck under an object in a natural disaster, or if a string is tightly tied around a finger or toe.

  • Wet gangrene: Wet gangrene is most often caused by a bacterial infection, but it can also be caused by a severe burn or frostbite. Wet gangrene can spread quickly and be fatal.

  • Gas gangrene: Gas gangrene is also caused by bacterial infections, most often Clostridium perfringens. It occurs in deep wounds, such as surgical incisions or a deep injury. It is called gas gangrene because the infection releases gas from toxins that build up. Gas gangrene can also progress very quickly and be fatal.

  • Internal gangrene: If the blood supply to an internal organ, such as the appendix or colon, is cut off, the result can be internal gangrene. It is life-threatening if not quickly recognized and treated.

  • Fournier’s gangrene: This type of gangrene is located in the genital area, including the scrotum, penis or perineum (the skin between the genitals and the anus). It is usually caused by an infection, but it is also a rare side effect to some medications.

  • Meleney’s gangrene: A rare form of gangrene, Meleney’s gangrene can occur in a surgical wound and is often fatal.

What are the symptoms of gangrene?

Gangrene symptoms depend on which part of the body is affected.

Common symptoms of gangrene of the skin

The most common symptoms of gangrene affecting the skin are:

  • Blisters

  • Change in skin color starting with paler than usual, and then progressing to bluish, purple, and black (although the skin could appear brown or red)

  • Cold skin when touched

  • Pain

  • Swelling

If the gangrene is caused by an infection, there also may be:

Common symptoms of internal gangrene 

The most common symptoms of internal gangrene include:

  • Fever

  • Severe pain

Untreated gangrene is a medical emergency and is life-threatening. Seek immediate medical care (call 911) if you or someone you are with, has any of the symptoms lifted above.

What does gangrene look like?

Gangrene can result when blood supply is cut off to tissue, such as if a child accidentally ties a string tightly around his or her foot for an extended time.

Illustration of gangrene on foot of child

One complication of diabetes is reduced blood flow to the extremities, resulting in diabetic ulcers that can progress into gangrene.

Diabetic foot ulcer illustration

What causes gangrene?

Any condition that interrupts the blood supply to body tissue can cause gangrene. Children who wrap a string or thread around a finger or toe can develop gangrene if the circulation is cut off for too long, for example.

The most common causes of gangrene include:

What are the risk factors for gangrene?

A number of factors increase the risk of developing gangrene. Not all people with these risk factors will get gangrene, but they should be watchful for signs and symptoms.

Risk factors for gangrene include:

  • Health conditions that affect blood flow, such as diabetes, Raynaud’s disease, or peripheral artery disease

  • Impaired immune system, either because of a health condition or medications, such as corticosteroids or chemotherapy

  • Obesity

  • Smoking

  • Surgery or any trauma to the skin

Reducing your risk of gangrene

You may be able to lower your risk of developing gangrene by:

  • Avoiding conditions with increased risk of frostbite

  • Following your treatment plan if you have a chronic illnesses

  • Losing weight if obese

  • Not smoking

  • Preventing infections and treating infections early when they do occur

Speak with your doctor if you have any injuries to your skin that are not healing or are showing signs of infection. Discuss your risk factors with your doctor to see what you can do to reduce your risk of gangrene.

How do doctors diagnose gangrene?

Doctors diagnose gangrene of the skin with a physical exam. Internal gangrene is not as obvious and requires testing. Your doctor or licensed healthcare practitioner will ask you several questions related to the symptoms including:

  • Do you have any health conditions that could make you susceptible to infections?

  • Have you had an injury or trauma to the area?

  • How long have you had the symptoms?

  • Are you experiencing any other symptoms, such as fever or pain?

Tests may include:

  • Blood tests, to look for signs of infection

  • Blood circulation tests, or vascular studies, to check how well blood flows through the affected tissue

  • Swabs of any pus or discharge from the skin, also to check for infection

  • Imaging tests, such as computed tomography (CT) scans or magnetic resonance imaging (MRI), to visualize the organs and internal body tissue

  • Exploratory surgery to look for signs of gangrene internally

What are the treatments for gangrene?

Gangrene can quickly become life-threatening so immediate treatment is vital. If gangrene is caused by a bacterial infection, treatment with antibiotics is essential. This is to prevent the infection from spreading or progressing to sepsis and septic shock.

Some non-surgical treatments may successfully treat skin gangrene, avoiding the need for surgery. They include:

  • Hyperbaric oxygen therapy. Patients lie in a pressurized chamber that increases the amount of oxygen they inhale. The higher oxygen levels in the blood can help kill the bacteria and speed up wound healing. 

  • Maggot therapy. Maggot therapy is an ancient treatment to remove dead tissue, a process known as debridement. Modern maggot therapy uses specially grown, sterile larvae that are placed on the wound. They eat the dead tissue, not touching the healthy tissue. The larvae are removed and replaced with others as needed.

If non-surgical treatments are not effective or not an option, surgery may help stop gangrene spread. Surgical procedures for gangrene include:

  • Surgical debridement. A surgeon removes the infected and dead tissue. The goal is to remove as little healthy tissue as possible while ensuring all the dead and infected tissue is removed.

  • Amputation. If the gangrenous area is too large for debridement, a surgeon may need to amputate the affected part, such as the foot or fingers.

  • Vascular surgery. If gangrene occurs because of poor blood circulation, a surgeon may perform vascular surgery (to the blood vessels) to try to improve the circulation and keep the tissue as healthy as possible.

Internal gangrene must be treated with surgery to remove the dead tissue.

What are the potential complications of gangrene?

If the gangrenous tissue covers too large an area for debridement, amputation may be necessary. Surgeons try to remove as little of the limb as possible to limit the effect of the amputation. Sometimes after the initial surgery, the surgeon may need to operate again to remove more tissue. You may need to use an artificial limb following amputation.

Complications from internal gangrene are related to the affected part of the body. If the gangrenous tissue is on the appendix, for example, the organ can be removed. However, if the gangrenous tissue is on the bowel, you may need a temporary colostomy until the operative site is fully healed, or a permanent colostomy if too much of the bowel is removed.

Untreated gangrene or aggressive untreatable gangrene can lead to death.

Getting medical help at the first signs of gangrene will help reduce the risk of complications.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jul 19
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Gabrielsen P. How Maggots Heal Wounds. Science. Dec. 6, 2012.
  2. Gangrene. Mayo Clinic.
  3. Gangrene. Johns Hopkins Medicine.
  4. Gangrene. MedlinePlus, National Library of Medicine, National Institutes of Health.
  5. Gangrene. Cleveland Clinic.
  6. Dry Gangrene. DermNet NZ.
  7. Fournier Gangrene. National Organization for Rare Disorders.
  8. FDA warns about rare occurrences of a serious infection of the genital area with SGLT2 inhibitors for diabetes. FDA.
  9. Gupta A, Gupta J, Sharma A. Meleney’s Gangrene: Simple Debridement and Antiseptic Dressings can save a Patient’s Life. Journal of Medical Science and Clinical Research. Volume 05 Issue 01 January 2017.
  10. What are vascular studies? Johns Hopkins Medicine.