Restless legs syndrome (also known as RLS, Wittmaack-Ekbom's syndrome, and sometimes, but inaccurately, referred to as Nocturnal myoclonus) is a disorder that evokes an irresistible urge to move one's body to stop uncomfortable or odd sensations.
RLS typically affects a person's legs, but can also affect their arms or torso. Moving the affected body part amends the sensations and provides short-term relief. The sensation felt in the legs or arms can most closely be compared to a burning, itching, or tickling sensation in the muscles.