Paresthesia

Paresthesia (or paraesthesia) is a sensation of the skin that may feel like numbness (hypoesthesia), tingling, pricking, chilling, or burning. It can be temporary or chronic and has many possible underlying causes. Paresthesia is usually painless and can occur anywhere on the body, but does most commonly in the arms and legs. The most familiar kind of paresthesia is the sensation known as pins and needles after having a limb "fall asleep" (obdormition). This is typically achieved by not moving the limb for a long period of time. Hitting the ulnar nerve (the "funny bone", actually a nerve) also induces paresthesias. A less common kind is formication, the sensation of insects crawling on or under the skin.