When the long blood vessels supplying blood to the arms and legs become blocked (ischemic), patient will experience painful sensations in their calves when they walked which slowly become excruciating painful at rest. When the condition worsens, the patients will not be able to feel any pain from their legs and they will not know if there are any small ulcers or cuts on their legs. As a result, a small ulcer which goes unnoticed becomes bigger and can sometimes become infected. In the worst situations, infection might lead towards gangrene and septicaemia. Severe rest pain and/or ulcerations of ischemic limbs are defined as the state of chronic critical limb ischemia and at this point, amputation of the affected limb is suggested.