Gangrene is a serious condition in which a loss of blood supply causes body tissue to die. It can affect any part of the body but typically starts in the toes, feet, fingers and hands.

Gangrene can occur as a result of an injury, infection or a long-term condition affecting blood circulation.

Symptoms of gangrene include:

redness and swelling in the affected area

either a loss of sensation or severe pain in the affected area

sores or blisters in the affected area that bleed or produce a foul-smelling pus

You should see your GP immediately if you are worried you may have gangrene.


Who is affected

Anyone can develop gangrene, particularly after a serious injury, but there are certain groups of people who are more at risk.

These include people with long-term conditions that can affect the blood vessels, such as:

diabetes – a condition that causes a person's blood sugar level to become too high

atherosclerosis – where arteries narrow and become clogged with a fatty substance known as plaque

peripheral arterial disease – where a build-up of fatty deposits in the arteries restricts blood supply to leg muscles

Raynaud's phenomenon – where blood vessels in certain parts of the body, usually the fingers or toes, react abnormally to cold temperatures

During 2012-13, around 35,000 cases of gangrene were seen in hospitals in England.


How gangrene is treated

The earlier treatment begins, the more successful it is likely to be. The main treatments include surgery to remove damaged tissue (known as debridement) and antibiotics to treat any underlying infection.

In some cases, you may have surgery to restore the blood flow to the affected area.

In more severe cases, it may be necessary to remove an entire body part such as a toe, foot, or lower leg. This is known as amputation.

Preventing gangrene

Many cases of gangrene can be prevented.

If you have a condition that increases your risk of gangrene, it’s important to have regular check-ups to assess the state of your feet and to report any problems to your GP as soon as possible.

Stopping smoking if you smoke and adopting a healthy lifestyle, with a low-fat diet and regular exercise, can also improve your circulation and reduce your risk of developing gangrene.


Diabetes and feet

Foot health is especially important for people with diabetes. Find out how to take care of your feet and when to get help


Page last reviewed: 27/01/2014


Symptoms of gangrene 

The symptoms of gangrene vary depending on the underlying cause. The condition can affect any part of the body, but typically starts in the toes, feet, fingers or hands.

General symptoms of gangrene include:

initial redness and swelling 

either a loss of sensation or severe pain in the affected area

sores or blisters that bleed or release a dirty-looking or foul-smelling discharge (if the gangrene is caused by an infection)

the skin becoming cold and pale

In some cases, the affected limb may feel heavy and pressing the skin may produce a crackling sound. These symptoms are caused by a build-up of gas under the skin.

If the area is infected, you may also have other signs related to the underyling infection, such as:

a high temperature (fever)

loss of appetite

rapid heartbeat and breathing



Without treatment the affected tissue will start to die. When this happens, the area changes colour from red to brown to purple or black, before shrivelling up and falling away from the surrounding healthy tissue.

When to seek medical advice

The earlier treatment begins, the more successful it is likely to be. Contact your GP immediately if you notice:

any of the symptoms of gangrene mentioned above

a persistent fever

a wound that is unusually slow to heal

When to seek emergency help

If bacteria from gangrene pass into your bloodstream, you could go intoseptic shock. This is a life-threatening condition that happens when an infection causes your blood pressure to drop to a dangerously low level.

Signs of septic shock include:

a rapid but weak pulse

dizziness when you stand up

a change in your mental state, such as confusion or disorientation

breathing difficulties



cold, clammy and pale skin


If you suspect that you or someone you know is in septic shock, dial 999 immediately and ask for an ambulance.

Causes of gangrene 

Gangrene can develop when the supply of blood to one or more areas of your body is interrupted.

This can happen as the result of an injury, an infection, or an underlying condition that affects your circulation.

Types of gangrene

There are several different types of gangrene, each with a different cause. The main types are:

Dry gangrene – when the blood flow to an area of the body becomes blocked.

Wet gangrene – caused by a combination of injury and a bacterial infection.

Gas gangrene – where an infection develops deep inside the body and the bacteria responsible begin releasing gas.

Necrotising fasciitis – caused by a serious bacterial infection that spreads quickly.

Internal gangrene – when the blood flow to an internal organ, usually the intestines, gallbladder or appendix, becomes blocked.

Who is most at risk?

People most at risk of gangrene include those with an underlying health condition that can affect the blood vessels and arteries (particularly if it is poorly managed), and those with a weakened immune system.

Conditions affecting the blood vessels

Conditions that can affect the blood vessels and increase your risk of gangrene include:

diabetes – a condition that causes a person's blood sugar level to become too high, which can result in damage to nerves and blood vessels (see below)

atherosclerosis – where arteries narrow and become clogged with a faFreadtty substance known as plaque

peripheral arterial disease – where a build-up of fatty deposits in the arteries restricts blood supply to leg muscles

Raynaud's phenomenon – where blood vessels in certain parts of the body, usually the fingers or toes, react abnormally to cold temperatures

As blood vessels are naturally narrow, any damage or extra narrowing has the potential to block blood flow to a part of the body and cause gangrene.


People with diabetes have an increased risk of developing gangrene because the high blood sugar levels associated with the condition can damage your nerves, particularly those in your feet, which can make it easy to injure yourself without realising.

High blood sugar can also damage your blood vessels, restricting the blood supply to your feet. Less blood means your feet will also receive fewer infection-fighting cells, so wounds will take longer to heal and are more likely to become infected.

Therefore, it is essential you take extra care of your feet if you have diabetes. 

Injuries and surgery

You are also at an increased risk of gangrene if you experience a traumatic injury or serious damage to your skin and tissues, such as:

a serious injury – for example, during a car accident

a burn


These injuries can cause a sudden loss of blood to an area of your body, and any open wounds can become infected with bacteria.

Some cases of gangrene occur as a result of infection that develops during surgery. However, advances in surgical techniques and infection control mean the chances of gangrene developing during surgery are small nowadays.

Weak immune system

If your immune system is seriously weakened, minor infections can become more serious and can lead to gangrene. A weak immune system can be caused by:

chemotherapy or radiotherapy



chronic alcohol misuse

injecting drugs, such as heroin


being over 60 (the older you are, the less efficient your immune system is)


kidney failure

However, for reasons that are unclear, some cases of gangrene occur in young and otherwise healthy people.


Diagnosing gangrene 

A diagnosis of gangrene is based on a combination of physical examination, medical history and tests.

Your doctor will want to find out if you have any long-term health conditions, or if you have recently experienced any injuries that could have caused the condition.

They will also examine the affected area to check for any obvious signs of gangrene, such as a foul odour or discolouration of the skin.

A number of tests and investigations can be carried out to confirm the diagnosis of gangrene. These include:

Blood tests to check for an infection.

Fluid or tissue culture – where a small sample of fluid or tissue from the affected area is tested to find out which bacteria are responsible for the condition and to determine the most effectiveantibiotic to treat it with.

Blood cultures – where a sample of blood is taken and put into special culture bottles and placed in a warm environment (incubated) to encourage the growth of bacteria so they can be examined further.

Imaging tests – a range of imaging tests, such as X-rays,magnetic resonance imaging (MRI) scans or computerised tomography (CT) scans can be used to confirm the presence and spread of gangrene. These tests can also be used to study blood vessels so any blockages can be identified.

Surgery – surgical examination under anaesthetic may be necessary to confirm a diagnosis of gangrene deeper inside the body.

As gangrene is a potentially serious condition, treatment is usually started before the results of any tests become available.

Treating gangrene 

Treatment for gangrene involves removing the affected tissue, preventing infection or treating any existing infection, and treating the problem that led to gangrene developing.

For example, if gangrene is caused by a poor blood supply, surgery may be used to repair damaged blood vessels.

Removing dead tissue

Surgery to cut out the dead tissue, known as debridement, is often necessary to prevent the gangrene from spreading and to allow the surrounding healthy tissue to heal.

Maggot therapy

In some cases, it may be possible to use 'maggot therapy' (‘biosurgery’) instead of conventional surgery to remove the dead tissue.

Certain types of maggot are ideal for this because they feed on dead and infected tissue but leave healthy tissue alone. They also help fight infection by releasing substances that kill bacteria and stimulate the healing process.

Maggots used for maggot therapy are specially bred in a laboratory using eggs that have been treated to remove bacteria. During maggot therapy, the tiny maggots are put on to the wound and covered with gauze, under a firm dressing. After a few days, the dressing is cut away and the maggots are removed.

A number of medical studies have shown maggot therapy can achieve more effective results than surgical debridement. However, because of the nature of this type of treatment, many people are reluctant to try it.


In severe cases of gangrene, where a whole body part – such as a finger, toe, or limb – is affected and debridement is unlikely to help,amputation may be considered.

Amputation can prevent gangrene spreading to other parts of the body and can be used to remove a severely damaged limb so an artificial (prosthetic) limb can be fitted.

Unless immediate treatment is needed in an emergency, a decision to amputate will only be made after a full discussion between you and the health professionals treating you.

Treating infection

If your gangrene is caused by an infection, you will usually be treated with antibiotic medication. These medications can be given as tablets or injections.

Injections are usually necessary if having surgery or if you have a severe infection. They allow bigger doses to be given and they are more likely to reach the affected area.

To counter the effects of infection and accelerate the healing process, you will also need fluids and nutrients into a vein (intravenous fluids) and may need blood transfusions.

Restoring the blood flow

In some cases, surgery may be carried out to restore the blood flow to the affected area. The main techniques used to achieve this are:

Bypass surgery – where the surgeon redirects the flow of blood and bypasses the blockage by connecting (grafting) one of your veins to a healthy part of an artery.

Angioplasty – where a tiny balloon is placed into a narrow or blocked artery and is inflated to open up the vessel. A small metal tube, known as a stent, may also be inserted into the artery to help keep it open.

Research suggests that both techniques are equally effective in restoring blood flow and preventing the need for amputation in the short-term. An angioplasty has the advantage of having a faster recovery time than bypass surgery, although it may not be as effective in the long-term as bypass surgery.

Hyperbaric oxygen therapy

An alternative treatment for some forms of gangrene is hyperbaric oxygen therapy.

During this treatment, you sit or lie down in a specially designed chamber filled with pressurised air. A plastic hood that provides pure oxygen for you to inhale is then placed over your head.

This treatment results in high levels of oxygen diffusing into your bloodstream and getting to the affected areas (even those with a poor blood supply), which speeds up healing.

If you have gangrene caused by a bacterial infection, the oxygen can also stop some types of bacteria (particularly the type responsible for gas gangrene) producing the toxins that allow the infection to spread, preventing further tissue damage.

Hyperbaric oxygen therapy has proved effective in treating gangrene resulting from infected diabetic foot ulcers, reducing the risk of amputation.

However, evidence relating to the effectiveness of hyperbaric oxygen therapy in treating other types of gangrene is limited and further research is required. Hyperbaric oxygen therapy is also currently not widely available in the UK.

Reconstructive surgery

Reconstructive surgery using a skin graft (skin taken from elsewhere on the body) may be used to cover the area of skin damaged by gangrene.

During a skin graft, the surgeon will remove healthy skin from another part of your body (usually a part that would be covered by clothing), and then reconnect it over the damaged area.


Preventing gangrene 

There are a number of things you can do to help lower your risk of developing gangrene. These are explained below.

Foot care

If you have diabetes or another long-term condition that can cause atherosclerosis (hardening or thickening of the arteries), it is important you take extra care of your feet.

If you have diabetes, you should have your feet checked at least once a year. However, more frequent check-ups may be required for those who have additional risk factors, such as peripheral neuropathy (numbness in the hands and feet), or a history of foot ulcers.

The advice listed below can help prevent a diabetic foot ulcer developing:

Check your feet daily for problems such as numbness, discolouration, breaks in the skin, pain or swelling. Report problems to your GP immediately.

Avoid walking barefoot outside and wearing shoes without socks.

Do not use chemical preparations for calluses, corns or ingrown toenails. Instead, contact a podiatrist (a healthcare professional who specialises in foot care).

Wash your feet daily with warm water. Afterwards, make sure you dry them thoroughly, particularly between the toes.

Wear shoes that fit well and don’t squeeze or rub. Ill-fitting shoes can cause corns and callouses, ulcers and nail problems.

If you have a history of foot ulcers, wearing specially designed therapeutic or orthopaedic shoes can help prevent further ulcers developing. Your podiatrist may be able to provide you with specially made-to-measure footwear, or they may be able to recommend a stockist.


Smoking can cause your arteries to become blocked, resulting in a loss of blood supply to your arms or legs. This is known as peripheral arterial disease (PAD).

If you decide to stop smoking, your GP will be able to refer you to an, which will provide dedicated help and advice about the best ways to give up. You can also call the Smoking Helpline on 0300 123 1044.

If you are committed to giving up smoking but do not want to be referred to a stop smoking service, your GP should be able to prescribe medical treatment to help with any withdrawal symptoms you may experience.


Eating an unhealthy diet high in fat will make any existing atherosclerosis worse and increase your risk of developing gangrene.

Continuing to eat high-fat foods will cause more fatty plaques to build-up in your arteries. This is because fatty foods contain cholesterol.

There are two types of fat – saturated and unsaturated. Avoid foods that contain saturated fats because they increase levels of bad cholesterol in your blood.

Foods high in saturated fat include:

meat pies

sausages and fatty cuts of meat


ghee (a type of butter often used in Indian cooking)



hard cheese

cakes and biscuits

food containing coconut or palm oil


Drinking excessive amounts of alcohol will cause your blood pressure to rise, and also raise the level of cholesterol in your blood.

Recommended daily limits of alcohol consumption are:

3-4 units for men

2-3 units for women

A unit of alcohol is equal to about half a pint of normal strength lager, half a standard glass of wine, or a pub measure (25ml) of spirits.


A healthy, well-balanced diet and regular exercise will help keep your blood pressure and cholesterol levels at a healthy level, helping prevent your blood vessels becoming damaged.

Unless advised otherwise by your doctor, you should be aiming for at least 150 minutes (two-and-a-half hours) of moderately intense physical exercise a week.

The definition of moderate intensity physical activity is any activity that increases your heart and breathing rate and may make you sweat but you are still able to hold a normal conversation.

Examples include:

fast walking

riding a bike on level ground or with few hills



Choose physical activities you enjoy, as you are more likely to continue doing them.

It is probably unrealistic to meet these exercise targets immediately if you have not exercised much in the past. Aim to start gradually and build up how much exercise you do over time.