Restless legs syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Restless legs syndrome is a neurological condition that causes an irresistible urge to move the legs. The movement is triggered by strange or uncomfortable feelings, often described as crawling, pulling, or itching, deep within both legs. The feelings usually occur while the affected person is sitting or lying down and are worse at night. Movement, such as kicking, stretching, rubbing, or pacing, make the discomfort go away, at least temporarily. The unpleasant feelings and the resulting need to move the legs often make it difficult for an affected person to fall asleep or stay asleep.

The signs and symptoms of restless legs syndrome range from mild to severe; people with mild cases may experience symptoms a few times a month, while those with more severe cases may have symptoms every night. In severe cases, the uncomfortable feelings can affect the arms or other parts of the body in addition to the legs.

Many people with restless legs syndrome also experience uncontrollable, repetitive leg movements that occur while they are sleeping or while relaxed or drowsy. When these movements occur during sleep, they are called periodic limb movements of sleep (PLMS); when they occur while a person is awake, they are called periodic limb movements of wakefulness (PLMW). It is unclear whether PLMS and PLMW are features of restless legs syndrome itself or represent similar, but separate, conditions.

Restless legs syndrome and PLMS can affect the quality and amount of sleep. As a result of these conditions, affected individuals may have difficulty concentrating during the day, and some develop mood swings, depression, or other health problems.

Researchers have described early-onset and late-onset forms of restless legs syndrome. The early-onset form begins before age 45, and sometimes as early as childhood. The signs and symptoms of this form usually worsen slowly with time. The late-onset form begins after age 45, and its signs and symptoms tend to worsen more rapidly.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Restless legs syndrome likely results from a combination of genetic and environmental factors, many of which are unknown.

Studies suggest that restless legs syndrome is related to a shortage (deficiency) of iron in certain parts of the brain. Iron is involved in several critical activities in brain cells, including the production of a chemical messenger (neurotransmitter) called dopamine. Among its many functions, dopamine triggers signals within the nervous system that help the brain control physical movement. Researchers believe that malfunction of the dopamine signaling system may underlie the abnormal movements in people with restless legs syndrome. However, it is unclear how iron deficiency is related to abnormal dopamine signaling, or how these changes in the brain lead to the particular signs and symptoms of the condition.

Variations in several genes have been studied as risk factors for restless legs syndrome. Most of these genes are thought to be involved in the development of nerve cells (neurons) before birth. It is unclear whether any of the genes play roles in brain iron levels or in dopamine signaling. Variations in known genes appear to account for only a small percentage of the risk of developing restless legs syndrome. Changes in other genes, which have not been identified, probably also contribute to this complex disorder. Researchers suspect that the early-onset form of restless legs syndrome is more likely than the late-onset form to have a genetic basis.

Nongenetic factors are also thought to play a role in restless legs syndrome. For example, several other disorders increase the risk of developing the condition. These include a life-threatening failure of kidney function called end-stage renal disease, diabetes mellitus, multiple sclerosis, rheumatoid arthritis, and Parkinson's disease. People with low iron levels associated with a shortage of red blood cells (anemia) and women who are pregnant are also more likely to develop restless legs syndrome. In these cases, the condition usually improves or goes away when iron levels increase or after the woman gives birth.

Restless legs syndrome can be triggered by medications, including certain drugs used to treat nausea, depression and other mental health disorders, colds and allergies, heart problems, and high blood pressure. Use of caffeine, nicotine, or alcohol can also trigger restless legs syndrome or make the signs and symptoms worse. In these cases, the condition usually improves or goes away once a person stops using these medications or substances.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

The inheritance pattern of restless legs syndrome is usually unclear because many genetic and environmental factors can be involved. The disorder often runs in families: 40 to 90 percent of affected individuals report having at least one affected first-degree relative, such as a parent or sibling, and many families have multiple affected family members. Studies suggest that the early-onset form of the disorder is more likely to run in families than the late-onset form.

In some affected families, restless legs syndrome appears to have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance suggests that one copy of an altered gene in each cell is sufficient to cause the disorder. However, the genetic changes associated with restless legs syndrome in these families have not been identified.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Restless legs syndrome is one of the most common sleep and movement disorders. It affects an estimated 5 to 10 percent of adults and 2 to 4 percent of children in the United States. For unknown reasons, the disorder affects women more often than men. The prevalence of restless legs syndrome increases with age.

Which doctor should you see?

The suggested department for discussing Restless legs syndrome is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which nervous-system findings help explain the symptoms?
• Would an assessment of walking, communication or daily function be helpful?
• Are rehabilitation or other specialist services relevant?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Restless legs syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.