Gangrene: Everything You Need to Know

Medically Reviewed By Megan Soliman, MD
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Gangrene is a serious condition in which body tissue dies due to infection or a loss of blood supply. Any part of the body can be gangrenous, though it typically starts in the toes, feet, fingers, and hands. If not treated quickly enough, gangrene can be fatal. Gangrene can occur due to a vascular problem that stops the blood flow, or it may happen because of a bacterial infection.

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 that it does not spread.

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

Read on to find out more about gangrene, including the different types of gangrene, how to identify symptoms, and the possible treatment options.

What is gangrene?

a woman is researching gangrene on a laptop
Jimena Roquero/Stocksy United

Gangrene occurs when the blood supply is cut off, causing body tissue to die. This can happen due to circulatory problems, an injury, or infection.

There are several types of gangrene. The main types of gangrene include:

  • Dry gangrene: Dry gangrene occurs if the blood supply is cut off from body tissue. This type of gangrene is also known as ischemia or ischemic gangrene. The area becomes dry, shrinks, and turns black.
  • Wet gangrene: Wet gangrene typically occurs due to a bacterial infection. The area may swell, drain fluid, and develop an unpleasant smell. Wet gangrene is more common among individuals who have diabetes and those with uncontrolled blood sugar levels.
  • Gas gangrene: Gas gangrene occurs due to 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: Internal gangrene happens when something cuts off the blood supply to an internal organ, such as the appendix or intestines.
  • 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 usually occurs due to an infection.
  • 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, such as the skin or the internal organs. Symptoms may also appear differently if an infection is present.

Common symptoms of gangrene of the skin

The most common symptoms of gangrene affecting the skin include:

  • swelling
  • loss of sensation in the affected area
  • severe pain in the affected area
  • cold and pale skin
  • sores or blisters that bleed

If the gangrene occurs due to an infection, you may also experience:

  • fever
  • unpleasant-smelling discharge
  • shivers
  • a rapid heartbeat
  • dizziness
  • a crackling sound when the affected area of tissue is pressed, in the case of gas gangrene

Untreated gangrene is a medical emergency and is life threatening. Seek immediate medical care if any of the symptoms above are present.

Treatments for gangrene

Gangrene can quickly become life threatening, so immediate treatment is vital. Your doctor will administer antibiotics, either in tablet form or as an injection, if gangrene occurs due to a bacterial infection. This is to prevent the infection from spreading or progressing to sepsis and septic shock.

Some nonsurgical treatments may successfully treat skin gangrene, avoiding the need for surgery. These treatments include:

  • Hyperbaric oxygen therapy: With this treatment, a person lies 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, in a process known as debridement. Modern maggot therapy uses specially grown, sterile larvae on the wound. These larvae eat the dead tissue, not touching the healthy tissue.

If nonsurgical treatments are not effective or not an option, surgery may help stop the spread of gangrene. Surgical procedures for gangrene include:

  • Surgical debridement: During 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.
  • Vascular surgery: If gangrene occurs because of insufficient blood circulation, a surgeon may perform vascular surgery to the blood vessels. The goal of this surgery is to improve the circulation and keep the tissue as healthy as possible.
  • 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. This is always a last resort.

What causes gangrene?

Tissue cells need sufficient blood flow to provide them with oxygen and other nutrients. Any interruption to that flow can cause the cells to die, resulting in gangrene.

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

The most common causes of gangrene include:

  • injury
  • infection
  • conditions that affect circulation

Who is at risk of 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:

Contact 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.

When should I contact a doctor about gangrene?

If you have any symptoms of gangrene, contact your doctor or seek medical attention immediately. If gangrene is treated early, treatment is more likely to be successful.

Diagnosing gangrene

Doctors diagnose gangrene of the skin with a physical exam. Internal gangrene is not as obvious and requires additional testing. Your doctor or other medical professional will ask you several questions related to the symptoms, which may include the following:

  • 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: These tests help determine if there are signs of an infection.
  • Fluid or tissue culture tests: With these tests, a healthcare professional will take a small sample from the affected area to find out which bacteria they need to treat.
  • Blood sampling: Doctors use this test to grow and examine present bacteria.
  • Imaging tests: These tests include X-rays, MRI scans, CT scans, or doppler ultrasounds.
  • Surgical examination: If your doctor needs to surgically examine the affected area, they will give you an anesthetic to prepare you for surgery.
  • Vascular studies: These studies check blood flow to the affected area.

Outlook for people with gangrene

The rate of survival with gangrene depends on how quickly diagnosis and treatment happen. Delayed treatment for many types of gangrene can be life threatening.

Prognosis may differ depending on the type of gangrene. Around 18–19.8% of people with Fournier’s gangrene, a type of bacterial gangrene affecting the groin area, do not survive. Comparatively, dry gangrene is fatal in around 20–25% of diabetic people who have it. Gas gangrene is also fatal in around 25% of trauma patients who develop it.

It is important that there is a diagnosis as soon as possible to reduce the risk of complications or death.

Is it possible to prevent gangrene?

Taking certain steps can help to lower your risk of developing gangrene. These can include:

  • Taking care of your feet: Check your feet daily for numbness, discoloration, swelling, or breaks in the skin. This is particularly important if you have diabetes or a condition that can cause atherosclerosis. Avoid walking barefoot or in shoes without socks, and consider wearing otrhopedic shoes if you are prone to foot ulcers.

View our article on how to care for your feet when you have diabetes for more information.

  • Stopping smoking: Smoking can cause the arteries to become blocked, which can lead to a loss of blood supply to your arms or legs. This results in a condition known as peripheral arterial disease, which puts you at risk of developing sores. These sores can then develop gangrene. Stopping smoking can help to reduce this risk.

View our hub on quitting smoking for information and advice to help you stop smoking.

  • Eating a well-balanced diet: A diet that is high in fat can increase your risk of developing gangrene while also worsening any existing atherosclerosis. A high fat diet encourages more fatty plaques to build up in the arteries. Avoid foods that contain saturated fats, such as:
    • fatty cuts of meat
    • butter
    • desserts such as cake or cookies
    • food containing coconut or palm oil

View our article on foods that cause a buildup of fatty plaques for more information.

  • Reducing alcohol intake: Excessive consumption of alcohol causes your blood pressure to rise. This, in turn, raises the level of cholesterol in your blood. Cholesterol buildup can increase the risk of gangrene.

View our article on alcohol consumption for information about measuring alcohol units.

  • Exercising regularly: Combining a balanced diet with regular exercise helps to keep your blood pressure and cholesterol levels healthy. In turn, this can help to prevent damage to your blood vessels.

View our article on exercises you can do from the comfort of your own home for more advice.

Complications of gangrene

If gangrene is left untreated or if diagnosis occurs too late, there may be complications. These can include:

  • large areas of scarring
  • damage that requires reconstructive surgery
  • amputation
  • organ failure
  • spread of infection throughout the body
  • death

Seek medical help at the first signs of gangrene to help reduce the risk of complications.


Gangrene occurs as a result of a bacterial infection or due to a vascular problem that prevents blood flow. If blood flow is not restored quickly enough, surgery may be required on the affected area. In some cases, amputation may be necessary.

Seeking medical attention as soon symptoms of gangrene appear will help to reduce the risk of complications. Steps to diagnosis include blood tests, imaging tests such as MRI or CT scans, and sampling small parts of the affected tissue.

There are certain steps that can help to reduce the risk of gangrene. Regularly checking your feet, particularly if you are diabetic or have a condition that can cause atherosclerosis, can help spot early risk factors for gangrene. Reducing alcohol intake, quitting smoking, and eating a healthier diet can all help reduce the risk of gangrene as well.

Seek medical attention as soon as you notice signs or symptoms of gangrene. A quicker diagnosis will increase the likelihood of an effective treatment plan, reducing the risk of complications.

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Medical Reviewer: Megan Soliman, MD
Last Review Date: 2022 Feb 28
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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.
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