Paresthesia can result from many different causes. It is often caused by nerve, spinal cord, or brain irritation or damage. It can be temporary (reversible) or permanent.While the nerve is squeezed, so are the arteries that feed blood to the nerve. The nerve can't work for long without a steady supply of oxygen and glucose. Anything that gets in the way of the nerve’s ability to send signals or with its blood supply causes a limb to “fall asleep.” For example, people in wheelchairs who sit for l