It is estimated that up to 7-10 percent of the U.S. population may have RLS. RLS occurs in both men and women, although women are more likely to have it than men. It may begin at any age. Many individuals who are severely affected are middle-aged or older, and the symptoms typically become more frequent and last longer with age.
People with RLS can sometimes experience remissions—spontaneous improvement over a period of weeks or months before symptoms reappear—usually during the early stages of the disorder. In general, however, symptoms become more severe over time.
In most cases, the cause of RLS is unknown (called primary RLS). However, RLS has a genetic component and can be found in families where the onset of symptoms is before age 40. Specific gene variants have been associated with RLS. Evidence indicates that low levels of iron in the brain also may be responsible for RLS.
Diagnosing RLS in children may be especially difficult, since it may be hard for children to describe what they are experiencing, when and how often the symptoms occur, and how long symptoms last. Pediatric RLS can sometimes be misdiagnosed as "growing pains" or attention deficit disorder.
RLS can be treated, with care directed toward relieving symptoms. Moving the affected limb(s) may provide temporary relief. Sometimes RLS symptoms can be controlled by finding and treating an associated medical condition, such as peripheral neuropathy, diabetes, or iron deficiency anemia.
