Definition: The numbness in a limb that comes from prolonged pressure on a sensory nerve, which then causes a pricking, tingling sensation called paresthesia.
The term comes from the Latin verb for falling asleep, which is exactly how we usually refer to this feeling—or lack of it—in our arms, legs, hands, or feet. Likewise, its aftermath, paresthesia, is often known as “pins and needles.”
Obdormition is harmless—although, as with any condition, you should tell your doctor if it becomes chronic. Shifting position or moving around to ease the pressure usually relieves it.