Man with gangrene holding his foot in pain
Man with gangrene holding his foot in pain
Man with gangrene holding his foot in pain


What is gangrene?

Gangrene is a dangerous and potentially fatal condition that happens when the blood flow to a large area of tissue is cut off. This causes the tissue to break down and die. Gangrene often turns the affected skin a greenish-black color. However, the word gangrene is not related to the color green, but to the condition itself. It comes from Greek and Latin words for a gnawing sore or decayed tissue. 

Gangrene comes in 2 forms, dry and wet:

  • Dry gangrene occurs when the blood supply to tissue is cut off. The area becomes dry, shrinks, and turns black. 
  • Wet gangrene occurs if bacteria invade this tissue. This makes the area swell, drain fluid, and smell bad.

What causes gangrene?

Gangrene happens when blood supply to certain tissues is stopped. This can happen due to:

  • An infection
  • An injury such as a burn or combat wound
  • A chronic disease

Chronic diseases that harm the circulatory system include diabetes, peripheral artery disease, and Raynaud's disease. These can often lead to gangrene. Traumatic injuries like burns or an infected dog bite may also stop blood flow. Severe cases where the skin freezes (frostbite) can also lead to gangrene.

Who is at risk for gangrene?

People with diabetes, peripheral artery disease, and Raynaud’s disease are at higher risk for gangrene. Skin infections, injuries, burns, dog bites, and frostbite also put people at risk for gangrene.

What are the symptoms of gangrene?

Symptoms of gangrene depend on its location and cause. Dry gangrene usually starts with a red line around the affected area. This area then turns dry and black.

These are other symptoms of gangrene:

  • Coldness and numbness in the affected area
  • Pain in or beyond the affected area
  • Redness and swelling around a wound (this is often present when wet gangrene develops)
  • Sores that keep cropping up in the same place
  • Persistent, unexplained fever, with a temperature higher than 100.4°F (38°C)
  • A bad-smelling wound
  • Striking discoloration of the skin, with shades of greenish-black, blue, red, or bronze
  • Pus or discharge from a wound
  • Blisters and a crackling feeling under the skin
  • Confusion, pain, fever, and low blood pressure, especially if the gangrene is internal
  • Shock

The earlier gangrene is treated, the more successful the treatment is likely to be. So if you have any of the above symptoms, seek immediate medical attention.

How is gangrene diagnosed?

If you have symptoms of gangrene, your healthcare team will give you a physical exam to check for signs of tissue death. They may also ask you about any chronic health conditions you have that could be linked to the gangrene.

Your healthcare provider may also want to do lab tests to check for gangrene. A higher than normal amount of white blood cells, for example, can mean you have an infection. Your healthcare provider may take samples of tissue or fluid from the affected area and look at in the lab. If your healthcare provider thinks you may have internal gangrene, he or she may order imaging tests or surgery to find out for sure.

How is gangrene treated?

Your healthcare provider will figure out the best treatment plan for you based on:

  • Your age, overall health, and medical history
  • How sick you are
  • How well you handle certain medicines, treatments, or therapies
  • If your condition is expected to get worse
  • The opinion of the healthcare providers involved in your care
  • Your opinion and preference

Treatment of gangrene will usually consist of 1 or more of these procedures:

  • Antibiotics. These medicines can be used to kill bacteria in the affected area. They are used only when wet gangrene is present
  • Surgery to remove the dead tissue. This is called debridement. It can help keep the gangrene from spreading to healthy tissues nearby. In cases where the gangrene is widespread, a finger, toe, or even a limb may need to be amputated.
  • Maggot debridement. This is a nonsurgical alternative to traditional debridement. During this procedure, clean fly larvae are placed on the affected area to eat away dead tissue and remove bacteria. This is a painless procedure.
  • Hyperbaric oxygen therapy. During this procedure, you are placed in a special pressurized chamber that administers oxygen at high pressures, forcing more oxygen into the affected area. This can promote speed healing and help kill bacteria. This treatment is especially effective in people who develop gangrene from diabetic foot ulcers.
  • Vascular surgery. If your gangrene is caused by poor blood flow, your healthcare provider may recommend surgery to improve your circulation. People whose gangrene is a result of a blocked artery, for example, may have bypass surgery or an angioplasty to fix the problem.

What are the complications of gangrene?

Because gangrene can spread rapidly over a large area of the body, the amount of dead tissue can be quite large. Treating these large areas may result in:

  • Large areas of scarring
  • The need for reconstructive surgery
  • Amputation

Severe cases of gangrene may lead to organ failure and even death.

What can I do to prevent gangrene?

You can help prevent gangrene by carefully watching any wounds you have and getting immediate attention if signs of infection develop. If you have certain conditions that can affect blood circulation (such as diabetes, peripheral vascular disease, Raynaud’s disease), follow your healthcare provider’s instructions on managing your condition very carefully.

When should I call my healthcare provider?

Gangrene is a medical emergency. The outlook with gangrene depends on the location and size of the affected area, as well as any other medical conditions you might have. Gangrene is often life-threatening, so immediate medical care is crucial. 

Key points

  • Gangrene is a dangerous and potentially fatal condition that happens when the blood flow to a large group of tissues is cut off.
  • People with diabetes, peripheral artery disease, and Raynaud’s disease are at higher risk for gangrene.
  • Symptoms of gangrene include coldness, numbness, pain, redness, or swelling in the affected area.
  • Amputation is sometimes needed.
  • Gangrene is a medical emergency.


Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.

Request an Appointment

Find a Doctor
Find a Doctor