FYI: It doesn't just happen while you're sleeping.

By Leah Groth
Updated August 11, 2020
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You are snuggled under the covers of your bed, on the couch watching television, or even driving home from work, when you experience an uncontrollable and somewhat unpleasant urge to move your legs. Sure, it could be a muscle strain or random twitch—or it could be something else going on in your brain. 

Restless legs syndrome—commonly known as a sleep disorder, but better characterized as neurological sensory disorder—affects about 7% to 10% of the US population, and women are more likely to have it than men, according to the National Institute of Neurological Disorders and Stroke (NINDS).

While the condition is difficult to describe to those who haven't experienced it—and is sometimes difficult to diagnose—there are treatments available. Here's what you need to know about restless legs syndrome, including signs and symptoms, what can cause the condition, and what to do about it.

What is restless legs syndrome?

Restless legs syndrome (RLS), also called Willis-Ekbom Disease, causes unpleasant, uncomfortable sensations in the legs and an irresistible urge to move them, according to the NINDS. It's a sensorimotor disorder, which is a disorder that affects both the sensory and motor systems in the body, Brian Koo, MD, associate professor of Neurology at Yale School of Medicine and Director, Yale Center for Restless Legs Syndrome Program, tells Health.

Symptoms of the condition usually occur during the late afternoon or evening hours, typically increasing at night when the body's at rest. But it doesn't occur only during sleep–per the NINDS, symptoms can occur anytime someone is inactive or sitting for an extended period of time. And while it usually occurs in the legs, in rare cases, people have reported similar sensations of restlessness in their arms, face, torso, and even genitals, says Dr. Koo.

What are the symptoms of restless legs syndrome, and how can it impact a person's life?

Overall, the symptoms of RLS consist of a distressing urge to move, often associated with sensory discomfort, says Dr. Koo. The NINDS adds that those specific sensations are often hard to describe, but many who suffer from the condition explain them as "aching, throbbing, pulling, itching, crawling, or creeping." Those sensations can occur on one side of the body, both sides, or can alternate between sides.

Because of these symptoms, "frequently, RLS symptoms impair sleep," says Dr. Koo. And while the initial symptoms are usually during the evening, those who suffer from RLS usually experience discomfort the following day as a result. The NINDS explains that RLS is one of several disorders that can cause exhaustion and daytime sleepiness, and can have a negative impact on mood, concentration, job and school performance, and personal relationships. In fact, "untreated moderate to severe RLS can lead to about a 20 percent decrease in work productivity and can contribute to depression and anxiety," per the NINDS.

RLS is also linked to periodic limb movement of sleep (PLMS)—about 80% of those who have RLS also have PLMS, which is characterized by involuntary leg or arm twitching or jerking during sleep that can happen every 15 to 40 seconds, sometimes throughout the night, per the NINDS. It should be noted, however, that while many people who have RLS also have PLMS, not everyone who has PLMS has RLS.

What causes restless legs syndrome?

In most cases, it is not entirely understood what causes RLS in those with no other underlying conditions—this is called primary RLS. However, Dr. Koo points out that there is evidence that low iron levels may be a contributing factor. The NINDS points out that “specific gene variants have been associated with RLS” and that it can be found in families where the onset of symptoms is before age 40. 

There is also, reportedly, “considerable evidence” that RLS is related to a dysfunction in the basal ganglia, one of the sections of the brain that control movement, that use the brain chemical dopamine. “Dopamine is needed to produce smooth, purposeful muscle activity and movement. Disruption of these pathways frequently results in involuntary movements,” the NINDS explains.

That said, RLS has also been found to be connected to the following underlying conditions or factors, according to both the NINDS and Dr. Koo:

  • End-stage renal disease and hemodialysis
  • Certain medications like antinausea drugs, antipsychotic drugs, antidepressants, and some antihistamines
  • Alcohol, nicotine, and caffeine use
  • Pregnancy
  • Neuropathy or nerve damage
  • Neurologic diseases like multiple sclerosis or Parkinson's disease

How is restless legs syndrome diagnosed, and how is it treated?

RLS is diagnosed clinically by assessing if a person has the stereotypical symptoms, explains Dr. Koo. “RLS most commonly becomes clinically apparent, when sleep onset and maintenance are disrupted,” he says. While there is no specific test for RLS, a doctor evaluates each case based on five basic criteria, per the NINDS: 

  • A strong and often overwhelming need or urge to move the legs that is often associated with abnormal, unpleasant, or uncomfortable sensations.
  • The urge to move the legs starts or get worse during rest or inactivity.
  • The urge to move the legs is at least temporarily and partially or totally relieved by movements. 
  • The urge to move the legs starts or is aggravated in the evening or night.
  • The above four features are not due to any other medical or behavioral condition.

There's currently no definitive cure for RLS, but treatment focuses on controlling the condition, relieving symptoms, and increasing periods of restful sleep. Dr. Koo explains that ensuring that iron levels are normal, ruling out other sleep disorders which can exacerbate RLS, and eliminating habits which can make RLS worse, including alcohol and caffeine, are all the first steps in treatment. 

As far as medications go, quite a few can be used to treat RLS. The first line of treatment consists of anti-seizure medications, like gabapentin or pregabalin. Dopamine agents, mostly used to treat Parkinson’s disease, can also be effective, as can opiates, which are primarily used in only cases with severe RLS specific side effects, says Dr. Koo.

Unfortunately, RLS is a lifelong condition, per the NINDS, but with current therapies symptoms can be minimized and restful sleep can be achieved. While it's always wise to see a doctor if RLS is disrupting your daily (and nightly) life, if RLS symptoms are mild and they don't produce significant discomfort or sleep disruption, the NINDS says the condition may not need treatment.

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