Restless Legs Syndrome (RLS) is a chronic sensorimotor disorder characterized by very unpleasant sensations in the legs and the compelling need to move the legs, usually experienced when trying to fall asleep. Other triggering situations for RLS are periods of inactivity such as long car trips, sitting in a (movie) theatre and long-distance flights. The unpleasant sensations, usually in the calves, are described as a type of cramp, soreness or a creeping, crawling feeling, and range in severity from uncomfortable to irritating to painful. In addition, Periodic Limb Movement Disorder (PLMD), which is characterized by involuntary leg twitching or jerking movements during sleep, is highly associated with RLS. Eventually RLS can lead to sleep disturbances, which can manifest itself in overall daytime fatigue, poor performance and depression. The quality of life can be severely affected by RLS.