Most amputations in the UK are carried out on people who have severely reduced blood circulation in one of their legs or feet as a result of peripheral arterial disease (PAD) or the complications of diabetes.

Other reasons why amputation may be considered include:

• serious injury (trauma) to a limb – for example, in a traffic accident
• serious infections
• cancer affecting the skin or bone of a limb

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.

Peripheral arterial disease (PAD)

PAD is a common condition in which a build-up of fatty deposits in the arteries (atherosclerosis) restricts blood supply to leg muscles.

In some cases, a complication called critical limb ischemia (CLI) can occur in one or both legs. This is where blood flow to the legs becomes severely restricted.

Symptoms of CLI can include:

• severe burning pain in your legs and feet, even when resting
• your skin becoming cold, pale, shiny, smooth and dry
• wounds and ulcers (open sores) on your legs and feet that don't heal
• the muscles in your legs beginning to waste away
• your skin changing colour, from red to brown to purple or black (gangrene)

CLI can sometimes be treated using an angioplasty or bypass graft (see treating PAD for more information on these operations) to restore blood flow to the affected leg. These are more likely to be successful if carried out early. 

However, even if these techniques are an option, they aren't always successful and you may still need to have an amputation.

Diabetes

Diabetes is a lifelong condition that causes a person's blood sugar level to become too high.

If you have diabetes, high blood sugar levels can damage your nerves (peripheral neuropathy) and blood vessels – particularly those in your feet.

Nerve damage can reduce the sensation in your feet, meaning you can injure your feet and develop a foot ulcer without realising it. Blood vessel damage can also reduce the blood supply to your feet, meaning ulcers take longer to heal and are more likely to become infected.

These infections can spread rapidly through the foot and up into the leg, and an amputation may be necessary to prevent it spreading further. Therefore, it's very important to seek help early to prevent amputation.

Trauma

Amputation may also 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)

Amputation may be considered in these cases if there is little chance of saving the injured body part, or if it is thought that amputation may lead to a quicker recovery and have a better long-term outcome in terms of the activities you will eventually be able to do.

Other reasons

Less common reasons why amputation may be considered 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)
• serious infections – such as an infection of the bone (osteomyelitis) or necrotising fasciitis (a 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