Amputation, the surgical removal of a body part, becomes necessary when a disease or injury causes severe damage to the limb to the point that it cannot heal. The affected body tissue begins to die and gets infected since there is limited circulation of blood to the limb or extremity, according to the National Health Service.
Narrowing or damage of the arteries can cause poor circulation of blood to parts of the body, a condition known as peripheral arterial disease. The disease results in the death and subsequent infection of the affected body part, necessitating amputation, according to WebMD.
According to WebMD and MedlinePlus, other reasons for amputation include cancerous tumors; neuroma, a thickening of nerve tissue; wounds that do not heal; and severe trauma due to automobile accident, frostbite or burns. Serious infections that do not heal after treatment could also lead to amputation. The rationale is that unless the affected tissue or body part is amputated, it can act as a stronghold for bacterial multiplication. Such bacteria could spread to other body parts, causing more tissue damage. In the case of cancerous tumors, amputation is performed to prevent the disease from spreading to other parts of the body.