What Is Restless Legs Syndrome?
Restless legs syndrome (RLS) is one of the most common sleep disorders. It causes unpleasant sensations in the legs. People describe these sensations as aching, throbbing, itching, pulling, or tingling. Twitching, jerking, and the irresistible urge to move the legs also happens.1-2
The unpleasant creeping, tingling feelings are most often felt deep in the lower legs, between the knees and ankles. But, the sensations may also be felt in the thighs or feet, and less often in the arms or head. Usually, the feelings happen in both legs.2
These feelings most often occur in the late afternoon or evening when a person is sitting or resting. However, some people feel these symptoms during the day when sitting still for a long time. It can be especially uncomfortable to sit through long meetings, movies, or plane rides. The discomfort usually gets better with movement.1,3
People with RLS may have trouble falling or staying asleep. This can lead to fatigue, daytime sleepiness, trouble concentrating, and poor moods. When moderate to severe RLS is left untreated, it can lead to a 20 percent drop in work productivity.1,4
Restless legs syndrome and PLMD
More than 80 percent of those with RLS also have periodic limb movement disorder (PLMD). In general, RLS happens when the person is awake and PLMD happens during sleep. RLS can be felt by the person but not seen by others. With PLMD, the legs, and sometimes arms, twitch or jerk every 15 to 40 seconds, sometimes all night. The kicking and jerking can make sleeping hard for bed partners.4
Restless legs in history
RLS is also called Willis-Ekbom disease. It was first described by British doctor Thomas Willis in 1672 as “so great a Restlessness and Tossings of their Members ensure that the diseased are no more able to sleep than if they were in a place of the greatest Torture.” In 1945, Dr. Karl Axel Ekbom named the condition “restless legs.” Dr. Ekbom’s patients complained of strange and tormenting prickling or tingling in the legs. Dr. Ekbom was the first to tie RLS to iron deficiency anemia and pregnancy. He was also the first to document that it runs in families.4-5
Who gets restless legs syndrome?
Studies estimate that between 5 and 15 percent of U.S. adults and 2 to 4 percent of children have RLS. Women are more likely to have RLS than men. It is more common in North America and Europe than in Asia.1
What causes restless legs syndrome?
Doctors believe RLS is caused by a combination of genetics and environment. It may be that low iron levels in the brain may interfere with dopamine and levodopa, 2 brain chemicals that control movement. However, more research is needed to better understand what causes RLS.1,2
RLS runs in some families. Between 40 and 90 percent of people with restless legs syndrome have at least 1 close relative with it. This genetic change is autosomal dominant in some families, meaning you only have to inherit one copy of the gene to get RLS. People whose RLS runs in the family usually have symptoms before age 40 and it gets worse slowly.1,6
Other health conditions
The most common health conditions tied to RLS are anemia, pregnancy, or end-stage kidney disease. However, people with these conditions are also at higher risk of developing RLS:1,6,7
- Multiple sclerosis
- Rheumatoid arthritis
- Parkinson’s disease
- Peripheral neuropathy
- Spinal cord injuries
Some drugs, caffeine, nicotine, and alcohol may make RLS worse or cause it in some people. The drugs most often tied to RLS symptoms are antihistamines, anti-nausea medicines, and some antidepressants.
What are the symptoms?
Symptoms of restless legs syndrome can be hard to explain to other people. The most common symptoms include:1
- Aching, throbbing, itching, pulling, crawling, or tingling sensations in the legs
- Pacing, moving the legs while sitting, or tossing in bed to relieve the feelings
- Trouble falling asleep or staying asleep
- Daytime sleepiness and trouble concentrating due to lack of good sleep
Symptoms may come and go over time, or get worse when taking certain medicines. Lack of sleep may also make RLS symptoms worse.1
How is restless legs syndrome diagnosed?
Most RLS is diagnosed by a doctor’s physical exam and medical history. Your doctor may ask you to fill out a sleep diary for 1 to 2 weeks. There is no blood test for RLS, though your doctor may check your blood iron levels. A sleep study in a lab may help determine if you have other sleep disorders such as periodic limb movement disorder or sleep apnea.
How is restless legs syndrome treated?
Mild to moderate RLS may be controlled with lifestyle changes, exercise, and over-the-counter and prescription devices. More severe RLS may be treated with a combination of lifestyle changes, iron supplements, and prescription drugs. The type of medicines prescribed for RLS include: