What Is Restless Legs Syndrome?
Restless legs syndrome (RLS) is a disorder that causes a strong urge to move your legs. This urge to move often occurs with strange and unpleasant feelings in your legs. Moving your legs relieves the urge and the unpleasant feelings.
People who have RLS describe the unpleasant feelings as creeping, crawling, pulling, itching, tingling, burning, aching, or electric shocks. Sometimes, the feelings also occur in the arms.
The urge to move and unpleasant feelings occur when you’re resting and inactive. They tend to be worse in the evening and at night and are temporarily relieved in the morning.
RLS can make it hard to fall asleep and stay asleep. It may make you feel tired and sleepy during the day. This can make it hard to learn, work, and do your normal routine. Not getting enough sleep also can cause depression, mood swings, or other health problems.
RLS can range from mild to severe based on:
The strength of your symptoms and how often they occur
How easily moving around relieves your symptoms
How much your symptoms disturb your sleep
One type of RLS usually starts early in life (before age 45) and tends to run in families. It may even start in childhood. Once this type of RLS starts, it usually lasts for the rest of your life. Over time, symptoms slowly get worse and occur more often. If you have a mild case, you may have long periods with no symptoms.
Another type of RLS usually starts later in life (after age 45). It generally doesn’t run in families. This type tends to have a more abrupt onset. The symptoms usually don’t get worse with age.
Some diseases, conditions, and medicines also may trigger RLS. For example, it has been associated with kidney failure, Parkinson disease, diabetes, rheumatoid arthritis, pregnancy, and iron deficiency. When a disease, condition, or medicine causes RLS, the symptoms usually start suddenly.
Medical conditions or medicines often cause or worsen the type of RLS that starts later in life.
RLS symptoms often get worse over time. However, some people’s symptoms go away for weeks to months.
If a condition or medicine triggers RLS, it may go away if the trigger is relieved or stopped. For example, RLS that occurs due to pregnancy tends to go away after giving birth. Kidney transplants (but not dialysis) relieve RLS linked to kidney failure.
Treatments for RLS include lifestyle changes and medicines. Some simple lifestyle changes often help relieve mild cases of RLS. Medicines usually can relieve or prevent the symptoms of more severe RLS. Research is ongoing to better understand the causes of RLS and to find better treatments.
What Causes Restless Legs Syndrome?
Faulty Use or Lack of Iron
Research suggests that restless legs syndrome (RLS) is mainly due to the faulty use or lack of iron in the brain. The brain uses iron to make the chemical dopamine and to control other brain activities. Dopamine works in the parts of the brain that control movement.
A number of conditions can affect how much iron is in the brain or how it’s used. These conditions include kidney failure, Parkinson disease, diabetes, rheumatoid arthritis, pregnancy, and iron deficiency. All of these conditions increase the risk of having RLS.
People whose family members have RLS also are more likely to develop the disorder. This suggests that genetics may contribute to the faulty use or lack of iron in the brain that triggers RLS.
Nerve damage in the legs or feet and sometimes in the arms or hands may cause or worsen RLS. Several conditions can cause such nerve damage, including diabetes.
Medicines and Substances
Certain medicines may trigger RLS. These include some:
Antinausea medicines (used to treat upset stomach)
Antidepressants (used to treat depression)
Antipsychotics (used to treat certain mental health disorders)
Cold and allergy medicines that contain antihistamines
Calcium channel blockers (used to treat heart problems and high blood pressure)
RLS symptoms usually get better or may even go away if the medicine is stopped.
Certain substances, such as alcohol and tobacco, also can trigger or worsen RLS symptoms. Symptoms may get better or go away if the substances are stopped.
Who Is At Risk for Restless Legs Syndrome?
Restless legs syndrome (RLS) may affect as many as 12 million people in the United States. More than half of the people who have RLS have family members with the condition.
RLS can affect people of any race or ethnic group, but the disorder is more common in people of Northern European descent. RLS affects both genders, but women are more likely to have it than men.
The number of cases of RLS rises with age. Many people who have RLS are diagnosed in middle age. However, in about 40 percent of RLS cases, symptoms start before age 20. People who develop RLS early in life usually have a family history of it.
People who have certain diseases or conditions or who take certain medicines are more likely to develop RLS. (For more information, see “What Causes Restless Legs Syndrome?”)
For example, RLS is common in pregnant women. It usually occurs during the last 3 months of pregnancy. The disorder usually improves or goes away after giving birth. Some women may continue to have symptoms after giving birth. Other women may develop RLS again later in life.
What Are the Signs and Symptoms of Restless Legs Syndrome?
The four key signs of restless legs syndrome (RLS) are:
A strong urge to move your legs. This urge often, but not always, occurs with unpleasant feelings in your legs. When the disorder is severe, you also may have the urge to move your arms.
Symptoms that start or get worse when you’re inactive. The urge to move increases when you’re sitting still or lying down and resting.
Relief from moving. Movement, especially walking, helps relieve the unpleasant feelings.
Symptoms that start or get worse in the evening or at night.
You must have all four of these signs to be diagnosed with RLS.
The Urge To Move
RLS gets its name from the urge to move the legs when sitting or lying down. This movement relieves the unpleasant feelings that RLS sometimes causes. Typical movements are:
Pacing and walking
Jiggling the legs
Stretching and flexing
Tossing and turning
Rubbing the legs
People who have RLS describe the unpleasant feelings in their limbs as creeping, crawling, pulling, itching, tingling, burning, aching, or electric shocks. More severe RLS symptoms may cause painful feelings. However, the pain usually is more of an ache than a sharp, stabbing pain.
Children may describe RLS symptoms differently than adults. Sometimes children with RLS are misdiagnosed as having ADHD.
The unpleasant feelings from RLS often occur in the lower legs (calves). But the feelings can occur at any place in the legs or feet. They also can occur in the arms.
The feelings seem to come from deep within the limbs, rather than from the surface. You usually will have the feelings in both legs. However, the feelings can occur in one leg, move from one leg to the other, or affect one leg more than the other.
People who have mild symptoms may only notice them when they’re still or awake for a long time, such as on a long airplane trip or when watching TV. If they fall asleep quickly, they may not have symptoms when lying down at night.
The unpleasant feelings from RLS aren’t the same as the leg cramps many people get at night. Leg cramps often are limited to certain muscle groups in the leg, which you can feel tightening. Leg cramps cause more severe pain and require stretching the affected muscle for relief.
Sometimes arthritis or peripheral arterial disease (PAD) can cause pain or discomfort in the legs. Moving the limbs usually worsens the discomfort instead of relieving it.
Periodic Limb Movement in Sleep
Most people who have RLS also have a condition called periodic limb movement in sleep (PLMS). PLMS causes your legs or arms to twitch or jerk about every 10 to 60 seconds during sleep. These movements cause you to wake up often and get less sleep.
PLMS usually affects the legs, but it also can affect the arms. Not everyone who has PLMS also has RLS.
Related Sleep Problems
The symptoms of RLS can make it hard to fall or stay asleep. If RLS disturbs your sleep, you may feel very tired during the day.
Lack of sleep may make it hard for you to concentrate at school or work. Not enough sleep also can cause depression, mood swings, or other health problems such as diabetes or high blood pressure.
How Is Restless Legs Syndrome Diagnosed?
Your doctor will diagnose restless legs syndrome (RLS) based on your symptoms, your medical and family histories, and the results from a physical exam and tests.
Your doctor will use this information to rule out other conditions that have symptoms similar to those of RLS.
Your primary care doctor usually can diagnose and treat RLS. However, he or she also may suggest that you see a sleep specialist or neurologist.
You must have the four key signs of RLS to be diagnosed with the condition.
Your doctor also will want to know how your symptoms are affecting your sleep and how alert you are during the day.
To help your doctor, you may want to keep a sleep diary. Use the diary to keep a daily record of how easy it is to fall and stay asleep, how much sleep you get at night, and how alert you feel during the day.
For a sample sleep diary, see the National Heart, Lung, and Blood Institute’s “Your Guide to Healthy Sleep.”
Medical and Family Histories
Your doctor may ask whether you have any of the diseases or conditions that can trigger RLS. These include kidney failure, Parkinson disease, diabetes, rheumatoid arthritis, pregnancy, and iron deficiency.
Your doctor also may want to know what medicines you take. Some medicines can trigger or worsen RLS.
Because the most common type of RLS tends to run in families, your doctor may ask whether any of your relatives have the disorder.
Your doctor will do a physical exam to check for underlying conditions that may trigger RLS. He or she also will check for other conditions that have symptoms similar to those of RLS.
Currently, no test can diagnose RLS. Still, your doctor will likely order blood tests to measure your iron levels. He or she also may order muscle or nerve tests. These tests can show whether you have a condition that may worsen RLS or that has symptoms similar to those of RLS.
Rarely, sleep studies are used to diagnose RLS. A sleep study measures how much and how well you sleep. Although RLS can cause a lack of sleep, this sign isn’t specific enough to diagnose RLS.
Researchers continue to study new tests to diagnose RLS.
Drug Therapy Trial
If your doctor thinks you have RLS, he or she may prescribe certain medicines to relieve your symptoms. These medicines, which are used to treat people who have Parkinson disease, also can relieve RLS symptoms. If the medicines relieve your symptoms, your doctor can confirm that you have RLS.