In many cases, no known cause for restless legs syndrome exists. Researchers suspect the condition may be due to an imbalance of the brain chemical dopamine. This chemical sends messages to control muscle movement.

Heredity

RLS runs in families in at least half the people with RLS, especially if the condition started at an early age. Researchers have identified sites on the chromosomes where genes for RLS may be present.

Pregnancy

Pregnancy or hormonal changes may temporarily worsen RLS signs and symptoms. Some women experience RLS for the first time during pregnancy, especially during their last trimester. However, for most of these women, signs and symptoms usually disappear quickly after delivery.

Related conditions

For the most part, restless legs syndrome isn't related to a serious underlying medical problem. However, RLS sometimes accompanies other conditions, such as:

  • Peripheral neuropathy. This damage to the nerves in your hands and feet is sometimes due to chronic diseases such as diabetes and alcoholism.
  • Iron deficiency. Even without anemia, iron deficiency can cause or worsen RLS. If you have a history of bleeding from your stomach or bowels, experience heavy menstrual periods, or repeatedly donate blood, you may have iron deficiency.
  • Kidney failure. If you have kidney failure, you may also have iron deficiency, often with anemia. When kidneys fail to function properly, iron stores in your blood can decrease. This, with other changes in body chemistry, may cause or worsen RLS.
Jan. 19, 2012

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