Restless Leg Syndrome is characterized by unpleasant tingling, creeping, crawling sensations in the legs which cause an urge to move the legs. These sensations occur when the person with RLS lies down or sits for prolonged periods of time. People with RLS may find it difficult to relax and fall asleep because of these strong urges to move their legs. RLS sufferers may feel sleepy during the day. The severity of symptoms varies from night to night and over the years as well.