Amputation - Why it is necessary 

Why amputation is necessary 

The most common reasons for carrying out an amputation are gangrene, atherosclerosis (where the arteries become narrowed and hardened), infection or trauma, where there is a serious injury to a limb or part of a limb.

These, and other less common reasons, are explained in more detail below.

Gangrene from a diabetic foot ulcer

A diabetic foot ulcer is an open sore that develops on the feet of people with diabetes.

High blood sugar causes damage to the nerves (peripheral neuropathy) and the blood vessels, particularly in your feet.

Therefore, the reduced sensation of the nerves means you are more likely to develop an ulcer, and the reduced blood supply means the ulcer is more likely to become infected. The infection is likely to further restrict blood supply, leading to gangrene (decay and death of body tissues).

Once gangrene has developed, it is sometimes necessary to amputate the affected limb to prevent the spread of infection and further damage to healthy tissue.


Atherosclerosis is a potentially serious condition that gets worse over time. The body’s arteries become clogged by fatty substances such as cholesterol.

You are more likely to get atherosclerosis if you smoke, if you're obese or have high high cholesterol or high blood pressure

Many people with atherosclerosis go on to develop a condition called peripheral arterial disease, which occurs when there is a blockage in the arteries of your limbs (in most cases, your legs).

In most severe cases of peripheral arterial disease, the blood supply to the lower limbs can become blocked, leading to the development of gangrene, which may then require revascularisation (restoration or improvement of blood supply) or amputation.


Amputation may be necessary if a limb has been severely injured. Examples of injury include:  

  • crush injuries, such as your arm or leg being severely crushed in a car crash
  • blast injuries, such as those experienced by soldiers wounded by explosive devices
  • avulsion injuries, where a body part is torn away from the body, such as a dog biting your finger off
  • guillotine injuries, where a limb or part of a limb is cut entirely or almost entirely away from the body, such as accidentally cutting off your thumb with a power saw
  • severe burns (including chemical burns)

Less common reasons

Less common reasons for amputation include:

  • cancers that develop inside the skin or bone of a limb, such as osteosarcoma (a type of bone cancer) or malignant melanoma (a type of skin cancer)
  • infections, such as an infection of the bone (osteomyelitis) or necrotising fasciitis (a serious type of bacterial skin infection sometimes referred to as flesh-eating bacteria)
  • Buerger's disease, a rare condition where blood vessels supplying the hands, arms, feet and legs become swollen and blocked, which can sometimes lead to gangrene and infection

Page last reviewed: 11/07/2012

Next review due: 11/07/2014


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Support groups

Being told you need an amputation can be a devastating and frightening experience. However, while adjusting to life with an amputation can be challenging, there is no reason why you cannot enjoy a good quality of life.  

You may find it useful to contact a support group for people living with amputations. The UK Limb Loss Information Centre website has information and advice as well as details of various local support groups.

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