Restless legs syndrome (RLS) is a condition in which your legs feel extremely uncomfortable while you're sitting or lying down. The condition usually makes you feel like getting up and moving around. In doing so, the unpleasant feeling goes away.

The disorder affects both sexes, can begin at any age and may worsen as you get older. Restless legs syndrome can disrupt sleep - leading to daytime drowsiness - and make traveling difficult.

A number of simple self-care steps and lifestyle changes may benefit you. Medications also help many people with restless legs syndrome.

Signs and symptoms

People typically describe the unpleasant limb sensations of restless legs syndrome as "deep-seated, creeping, crawling, jittery, tingling, burning or aching" feelings in their calves, thighs, feet or arms. Sometimes the sensations defy description. People usually don't describe the condition as a muscle cramp or numbness. Common characteristics of the signs and symptoms include:

• Origination during inactivity. The sensation typically begins while you're lying down or sitting for an extended period of time, such as in a car, airplane or movie theater.

• Relief by movement. The sensation of RLS lessens if you get up and move. People combat the sensation of restless legs in a number of ways — by stretching, jiggling their legs, pacing the floor, exercising or walking. This compelling desire to move is what gives restless legs syndrome its name.

• Worsening of symptoms in the evening. Symptoms typically aren't noticeable during the day but are felt primarily at night.

• Nighttime leg twitching. RLS is associated with periodic limb movement disorder (PLMD). Doctors used to call this condition myoclonus, but now they refer to it as PLMD. With PLMD you involuntarily flex and extend your legs while sleeping — without being aware you're doing it — often resulting in a restless night's sleep for your bed partner. Hundreds of these twitching or kicking movements may occur throughout the night. If you have severe RLS, these involuntary kicking movements may also occur while you're awake. PLMD is common in older adults, even without RLS, and doesn't always disrupt sleep. More than 80 percent of people with RLS also experience PLMD.

Most people with RLS find it difficult to get to sleep or stay asleep. Insomnia may lead to excessive daytime drowsiness, but RLS may prevent you from enjoying a daytime nap.

Although restless legs syndrome doesn't lead to other serious conditions, symptoms can range from bothersome to incapacitating. In fact, it's common for symptoms to fluctuate in severity, and occasionally symptoms disappear for periods of time.

RLS can develop at any age, even during childhood. Many adults who have RLS can recall being told as a child that they had growing pains or can remember parents rubbing their legs to help them fall asleep. The disorder is more common with increasing age.

• Insomnia

Causes

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.

Restless legs syndrome runs in families in up to half of 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. Stress generally makes restless legs syndrome worse.

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

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 restless legs syndrome. If you have a history of bleeding from your stomach or bowel, experience heavy menstrual periods or repeatedly donate blood, you may have iron deficiency.

• Kidney failure. If you have kidney failure, you also may have iron deficiency. When the kidney fails to function properly, iron stores in your blood can decrease and cause or worsen RLS.

People who have both RLS and an associated medical condition tend to develop signs and symptoms rapidly. In contrast, the disorder progresses more slowly in people whose RLS is unrelated to any other health problem.

• Insomnia

• Kidney failure

• Muscle cramp

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