Answer;
-Nerve
Damage to nerve and blood vessels can cause lack of feeling in the extremities resulting in amputations.
Step-by-step explanation;
-Conditions such as High blood sugar levels caused by diabetes can damage the nerves and blood vessels in the body. That includes the ones in the feet and legs. If the nerves are damaged, one might not feel pain or other symptoms of ulcers or infections.
-Numbness in the feet due to diabetic neuropathy (nerve damage) can make people less aware of injuries and foot ulcers. These ulcers may fail to heal, which can in turn lead to serious infections.