Having high blood sugar for many years can damage the blood vessels that bring oxygen to some nerves. High blood sugar can also hurt the covering on the nerves. Damaged nerves may stop sending messages. Or they may send messages too slowly or at the wrong times. Diabetes can damage the peripheral, autonomic, and cranial nerves.
Peripheral nerves go to the arms, hands, legs, and feet.
Damage to these nerves can make your arms, hands, legs, or feet feel numb. Also, you might not be able to feel pain, heat, or cold when you should. These feelings are often worse at night. They can make it hard to sleep. Most of the time these feelings are on both sides of your body, like in both of your feet.