What Is Restless Legs Syndrome (RLS)?

Restless legs syndrome (RLS) symptoms can make it hard to stay in bed, but causes can be addressed and effective treatments exist after diagnosis is made
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Restless legs syndrome (RLS) is one of those conditions that sounds a little too strange to be true, but if you have ever laid down to fall asleep and felt an uncomfortable sensation of bugs crawling under your skin, you may be all too familiar with what RLS is. This condition may leave you kicking your legs as you fall asleep, but a better understanding of the disorder, the symptoms, and its causes may lead to the diagnosis and treatment to obtain the rest that you need. Learn about restless legs syndrome, a condition also known as Willis-Ekbom disease.

What Is Restless Legs Syndrome (RLS)?

RLS is a movement disorder that is characterized by unpleasant feelings in the legs associated with a need to move. The sensations (called paresthesias) may include various descriptions:

  • Aches
  • Pulling
  • Itching
  • Bugs crawling under the skin
  • Tingling
  • Tightness
  • Electrical or jolting sensations

These symptoms typically come on during periods of rest, especially at night, and are relieved by movement. They may make it hard to fall or stay asleep, resulting in sleep-onset insomnia.

The condition is also called Willis-Ekbom disease, recognizing two doctors who described the symptoms historically. There are four features that are used to diagnose RLS and these include:

  1. An urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs.
  2. The urge to move or unpleasant sensations begin or worsen during periods of rest or inactivity such as lying or sitting.
  3. Sensations that are relieved by movement, such as walking or stretching, as long as the activity continues.
  4. Sensations that are worse during the evening or night.

Symptoms typically come on within 15 to 30 minutes of resting. In very severe cases, the problems may occur with any seated activity during the day, such as sitting in meetings or in a movie theater. Many find their symptoms are worsened on long flights or prolonged car rides. This may lead to fidgeting, constant movement, or the need to kick or massage the legs to relieve the symptoms. Some people are so bothered by the symptoms at night that they will get out of bed.

It is estimated that as many as 80 percent of individuals with RLS also may experience periodic limb movements of sleep (PLMS), which consist of rhythmic jerking leg movements involuntarily during sleep. The movements may be a flexion and extension at the ankle, and sometimes involve the knee. The pattern is intermittent during the night. These PLMS may be noted by a bed partner or on a diagnostic sleep study in a sleep center.

It is also important to recognize that leg cramps are a distinct condition. Leg cramps are when the muscles suddenly contract, causing pain, and may be associated with electrolyte imbalances.

How Common Is RLS?

Mild symptoms associated with RLS occur in 5 to 15 percent of the population. It seems to increase as we get older and occurs more commonly in women.

There are two types of RLS. The first, called primary (or idiopathic) RLS, has no clear cause and tends to run in families. The other type, called secondary RLS, occurs as the result of separate conditions, including iron deficiency, diabetes, pregnancy, peripheral neuropathy, and more.

Diagnosis and Treatment of Restless Legs Syndrome

RLS is diagnosed using the four criteria described above. It does not require any additional testing. A sleep study called a polysomnogram is not necessary but it may be helpful if the condition is resistant to treatment or if leg movements are suspected to be disruptive to the affected person or a bed partner.

A Word From Verywell

It is important to identify any contributing causes so that these can be addressed appropriately. Many people will have their serum ferritin level tested as iron deficiency often contributes. The treatment of RLS may include a combination of medications, exercises, and other therapies. Effective therapy can greatly reduce or eliminate these distressing symptoms.

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Article Sources

  • American Academy of Sleep Medicine. "International classification of sleep disorders: Diagnostic and coding manual." 3rd ed. 2014.

  • Allen, RP et al. "Restless legs syndrome prevalence and impact: REST general population study." Arch Intern Med. 2003;163:2323.
  • Hogl, B et al. "Restless legs syndrome: a community-based study of prevalence, severity, and risk factors." Neurology. 2005;64:1920.