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What Causes Restless Legs Syndrome?

Faulty Use of Iron or Lack of Iron

Research suggests that the main cause of restless legs syndrome (RLS) is a faulty use of iron or a lack of iron in the brain. The brain uses iron to make the chemical dopamine (DO-pah-meen) and to control other brain activities. Dopamine works in the parts of the brain that control movement.

Many conditions can affect how much iron is in the brain or how it's used. These conditions include kidney failure, Parkinson's disease, diabetes, rheumatoid arthritis, pregnancy, and iron deficiency. All of these conditions increase your risk of RLS.

People whose family members have RLS also are more likely to develop the disorder. This suggests that genetics may contribute to the faulty use of iron or lack of iron in the brain that triggers RLS.

Nerve Damage

Nerve damage in the legs or feet and sometimes in the arms or hands may cause or worsen RLS. Several conditions can cause this type of nerve damage, including diabetes.

Medicines and Substances

Certain medicines may trigger RLS. These include some:

  • Antinausea medicines (used to treat upset stomach)
  • Antidepressants (used to treat depression)
  • Antipsychotics (used to treat certain mental health disorders)
  • Cold and allergy medicines that contain antihistamines
  • Calcium channel blockers (used to treat heart problems and high blood pressure)

RLS symptoms usually get better or may even go away if the medicine is stopped.

Certain substances, such as alcohol and tobacco, also can trigger or worsen RLS symptoms. Symptoms may get better or go away if the substances are stopped.

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Restless Legs Syndrome Clinical Trials

Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Restless Legs Syndrome, visit

November 01, 2010 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.