Explain why people with poorly controlled diabetes are at risk for amputation?

People with poorly controlled diabetes are at risk of amputation due to damage of nerves in the extremities of the body. This damage to nerves is caused by chronically  high blood sugar. The condition, when it is caused by uncontrolled blood sugar is called diabetic neuropathy.

Diabetic neuropathy mostly affects the feet and they lose feeling, such that an affected person cannot  sense pain. When they develop an ulcer or small injury to the feet, it may often go unnoticed and with time become infected.  High blood sugar impairs  the normal healing process and the injury or ulcer may not heal quickly thus compounding the problem. The outcome of this is that the infected part e.g. a toe, may fester and even become gangrenous putting the whole bod at risk and thus the only away to save the rest of the body is removal by amputation.