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Gangrene is a serious condition where 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 that affects blood circulation.
Symptoms of gangrene include:
You should see your GP immediately if you're worried you may have gangrene.
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:
In 2013-14, more than 35,500 cases of gangrene were seen in hospitals in England.
Read more about the causes of gangrene.
The earlier treatment for gangrene begins, the more successful it's 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, surgery may be needed to restore 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.
Read more about treating gangrene.
Many cases of gangrene can be prevented.
If you have a condition that increases your risk of getting gangrene, such as diabetes, it's important you have regular check-ups to assess the state of your feet. Report any problems to your GP as soon as possible.
Read more about preventing gangrene.
The symptoms of gangrene vary depending on the underlying cause. It can affect any part of the body, but typically starts in the toes, feet, fingers or hands.
General symptoms of gangrene include:
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:
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.
The earlier treatment for gangrene begins, the more effective it's likely to be. Contact your GP immediately if you have:
If bacteria from gangrene pass into your bloodstream, you could go into septic shock. This is a life-threatening condition that occurs when an infection causes your blood pressure to drop to a dangerously low level.
Signs of septic shock include:
Dial 999 immediately to request an ambulance if you suspect that you or someone you know is in septic shock.
Gangrene can develop when the supply of blood to one or more areas of your body is interrupted.
This can occur as the result of an injury, an infection, or an underlying condition that affects your circulation.
There are several different types of gangrene, each with a different cause. The main types are:
People most at risk of gangrene are those with an underlying health condition that can affect the blood vessels and arteries (particularly if it's poorly managed), and those with a weakened immune system.
Conditions that can affect the blood vessels and increase your risk of developing gangrene include:
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. This is 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.
It's therefore important that you take extra care of your feet if you have diabetes. Read more about foot care in preventing gangrene.
You're also at an increased risk of developing gangrene if you experience a traumatic injury or serious damage to your skin and tissues, such as:
These injuries can cause a sudden loss of blood to an area of your body, and any open wounds can become infected with bacteria.
Gangrene can also occur as a result of an infection that develops during surgery. However, with advances in surgical techniques and infection control, the chances of gangrene developing during surgery are small nowadays.
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:
However, for reasons that are unclear, gangrene can sometimes occur in young and otherwise healthy people.
A diagnosis of gangrene is based on a combination of physical examination, medical history and tests.
Your doctor will want to find out whether you have any long-term health conditions, or if you've recently experienced any injuries that could have caused the condition.
They'll 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:
As gangrene is a potentially serious condition, treatment is usually started before the results of any tests become available.
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. If gangrene is caused by an infection, strong antibiotics may be used as well as surgery.
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.
In some cases, it may be possible to use larval debridement therapy, also known as biosurgery, instead of conventional surgery to remove the dead tissue.
Certain types of fly larvae 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 larval therapy are specially bred in a laboratory using eggs that have been treated to remove bacteria. The maggots are placed on the wound and covered with gauze, under a firm dressing, which keeps them on the wound (and out of sight). After a few days, the dressing is cut away and the maggots are removed.
Medical studies have shown larval debridement 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 emergency treatment is needed, a decision to amputate will only be made after a full discussion between you and the health professionals treating you.
Gangrene that's caused by an infection can usually be treated with antibiotics, which can be given as tablets or injections.
Injections are usually necessary if you need surgery or you have a severe infection. Injecting antibiotics directly into a vein allows larger doses to be given and means that they're more likely to reach the affected area.
To counter the effects of infection and accelerate the healing process, you'll also need fluids and nutrients into a vein (intravenous fluids) and you may need blood transfusions.
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:
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 is an alternative treatment for some types of gangrene.
During hyperbaric oxygen therapy, 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 placed over your head.
This treatment results in high levels of oxygen being dispersed into your bloodstream and reaching the affected areas (even those with a poor blood supply), which speeds up healing.
For 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 caused by 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 also isn't currently widely available in the UK.
Reconstructive surgery using a skin graft 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 reconnect it over the damaged area.
There are a number of things you can do to help lower your risk of developing gangrene.
If you have diabetes, you should have your feet checked at least once a year. However, you may need more frequent check-ups if you 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:
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 NHS Stop Smoking Service, which will provide dedicated help and advice about the best ways to give up. You can also call the NHS Smoking Helpline on 0300 123 1044.
If you're committed to giving up smoking but don't 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:
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:
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 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.
Moderate intensity physical activity is any activity that increases your heart and breathing rate. It may make you sweat but you'll still be able to hold a normal conversation. Examples include:
You should choose physical activities you enjoy because you're more likely to continue doing them.
It's probably unrealistic to meet these exercise targets immediately if you haven't exercised much in the past. Aim to start gradually and build up the amount of exercise you do over time.