Restless Legs Syndrome Fact Sheet: National Institute of Neurological Disorders and Stroke (NINDS)

What causes restless legs syndrome?

In most cases, the cause of RLS is unknown (referred to as idiopathic). A family history of the condition is seen in approximately 50 percent of such cases, suggesting a genetic form of the disorder. People with familial RLS tend to be younger when symptoms start and have a slower progression of the condition.

In other cases, RLS appears to be related to the following factors or conditions, although researchers do not yet know if these factors actually cause RLS.

• People with low iron levels or anemia may be prone to developing RLS. Once iron levels or anemia is corrected, patients may see a reduction in symptoms.
• Chronic diseases such as kidney failure, diabetes, Parkinson's disease, and peripheral neuropathy are associated with RLS. Treating the underlying condition often provides relief from RLS symptoms.
• Some pregnant women experience RLS, especially in their last trimester. For most of these women, symptoms usually disappear within 4 weeks after delivery.
• Certain medications-such as antinausea drugs (prochlorperazine or metoclopramide), antiseizure drugs (phenytoin or droperidol), antipsychotic drugs (haloperidol or phenothiazine derivatives), and some cold and allergy medications-may aggravate symptoms. Patients can talk with their physicians about the possibility of changing medications.

Researchers also have found that caffeine, alcohol, and tobacco may aggravate or trigger symptoms in patients who are predisposed to develop RLS. Some studies have shown that a reduction or complete elimination of such substances may relieve symptoms, although it remains unclear whether elimination of such substances can prevent RLS symptoms from occurring at all.