What causes restless legs syndrome (RLS)?

Causes of restless legs syndrome vary from person to person. In some cases, the cause is unknown. Other causes may include:
  • Low iron levels: Lack of iron causes problems with brain cell communication and can lead to restless legs syndrome. If you think you have restless legs syndrome caused by low iron, talk with your doctor before taking any supplements.
  • Diabetes: This lifelong condition can damage blood vessels and nerves that affect leg muscles, causing restless legs syndrome. By properly managing your diabetes, you may help prevent or improve restless legs syndrome.
  • Pregnancy: Many women have restless legs syndrome when they are pregnant. It usually goes away within a month of giving birth.
  • Medications: Some medications can cause restless legs syndrome or make it worse. They include: allergy medications, many antidepressants, antihistamines and over-the-counter sleep aids, and nearly all centrally active dopamine-receptor antagonists, including antinausea medications.

Restless legs syndrome (RLS) is a neurological disorder characterized by unpleasant sensations in the legs and an uncontrollable, and sometimes overwhelming, urge to move them for relief. Individuals affected with the disorder often describe the sensations as throbbing, polling, or creeping. The underlying are not known, but sometimes this condition may be associated with peripheral neuropathy, lumbar radiculopathy or iron deficiency anemia.

No one knows the exact cause of restless legs syndrome (RLS). However, many people with restless legs syndrome have a family history of the  condition. Other factors that seem to contribute to the development of RLS include using certain stimulants or antidepressants, being anemic, having kidney or liver problems, and being pregnant.

In most cases, the cause of restless legs syndrome (RLS) is unknown (referred to as idiopathic). A family history of the disorder 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 disorder.

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 the symptoms of RLS. Some pregnant women experience RLS, especially in their last trimester. For most of these women, symptoms usually disappear within four 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.

This answer is based on source information from the National Institute of Neurological Disorders and Stroke.

Although there is no known specific cause for restless leg syndrome, it is thought to be familial in some cases. Those who experience symptoms at a younger age (less than 30 years old) are more likely to have a family history of this condition. It has also been associated with iron deficiency, pregnancy, nerve damage, kidney failure, and certain medications such as antihistamines and beta-blockers. Treating these associated conditions can sometimes lead to resolution of restless leg syndrome as well.
Although the cause is unknown in most cases, certain factors may be associated with restless legs syndrome (RLS):
  • Family history. RLS seems to run in some families with parents passing on the condition to their children
  • Pregnancy. Some women experience RLS during pregnancy, especially in the last months. The symptoms usually disappear after delivery.
  • Low iron levels or anemia. If you have low iron levels or anemia, you are prone to developing RLS. The symptoms may improve once the iron level or anemia is corrected. Low ferritin levels (a protein used to carry iron in the blood) have also been associated with RLS. Some studies find that supplementing with iron can improve symptoms. Don't supplement on your own, however; too much iron can be dangerous and cause damage to vital organs such as the liver and heart. Talk to a healthcare professional first.
  • Chronic diseases. Kidney failure and other chronic diseases such as diabetes, rheumatoid arthritis and peripheral neuropathy can lead to RLS.
  • Caffeine intake. Reducing your intake of caffeine can improve symptoms.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.