Restless legs syndrome: symptoms, signs, and diagnosis

Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is built around one thing: an urge to move the legs. That urge usually comes with an uncomfortable sensation deep inside the leg — described as crawling, pulling, tugging, aching, itching, or an electric buzzing — rather than pain on the surface of the skin.

Two features make the pattern recognizable as restless legs syndrome rather than ordinary restlessness. It appears or worsens specifically when you are sitting or lying still — on a long flight, during a film, in bed at night — and it eases, at least partly and at least for a while, as soon as you move, stretch, or walk.

Restless legs syndrome is diagnosed by history, not by a blood test or a scan. The International Restless Legs Syndrome Study Group (IRLSSG) sets out five essential criteria, and every one of them must be met:

Restless legs syndrome rarely arrives with its clinical name attached. Most people describe the same five criteria above in their own words — every description below points back to the one diagnosis.

Most people describe restless legs syndrome as uncomfortable rather than sharply painful — closer to a deep, restless itch than a stabbing pain. But pain is real for a meaningful minority, and it is not simply "more severe" RLS: a 2025 twin-and-family study found painful and painless restless legs syndrome cluster with different other conditions — painless RLS with a history of iron deficiency, obesity, and Parkinson's disease; painful RLS with migraine, recurrent abdominal pain, and chronic spinal pain — suggesting the two are at least partly distinct sub-types rather than points on one severity scale.

Restless legs syndrome is also more common in painful rheumatic conditions: a meta-analysis of 17 studies found it in roughly a quarter to a third of people with rheumatoid arthritis, lupus, or ankylosing spondylitis, and in closer to 38% of people with fibromyalgia — well above general-population estimates. Osteoarthritis was the exception, at only about 4%, so the link is specifically with inflammatory/widespread-pain rheumatic conditions, not joint disease in general. This is an overlap, not proof that one causes the other: all of the underlying studies took a one-time snapshot rather than following people over time.

Restless legs syndrome getting worse in the evening or at night is not incidental — it is the fourth diagnostic criterion, and one of the condition's most consistent features. The circadian mechanism behind that timing, a dip in dopamine signalling meeting a nervous system that is already more excitable after dark, is covered in full on this site's page on how restless legs syndrome works, in its "evening: the circadian dip and hyperarousal" section.

Periodic limb movements in sleep (PLMS) are brief, repetitive leg twitches or jerks that happen while you are asleep, measured on a sleep study as a movement count per hour — not something the person having them reports themselves. Restless legs syndrome, by contrast, is defined by a conscious urge to move while awake and at rest. The two are related but not the same phenomenon: a randomized study found a dopamine agonist can suppress PLMS without correcting the same patients' cortical arousal instability, while a different drug did the reverse — direct evidence that PLMS and the rest of the RLS picture are at least partly separable mechanisms.

PLMS is also far from unique to restless legs syndrome. A population study of over 2,000 adults found a PLMS index above 15 events per hour in 28.6% of people, many of whom did not have restless legs syndrome at all — so leg movements found incidentally on a sleep study do not, by themselves, mean restless legs syndrome is present. The reverse pattern is more consistent: most, though not all, people with restless legs syndrome also show PLMS on a sleep study, but a restless legs syndrome diagnosis never depends on that finding. Periodic limb movement disorder — its own separate diagnosis for disruptive PLMS without restless legs syndrome — is covered on its own page.

There is no blood test or scan that confirms restless legs syndrome on its own. Diagnosis rests on a clinical history matched against the five criteria above, together with ruling out other explanations for the symptoms.

The fifth diagnostic criterion exists specifically to exclude conditions that can look like restless legs syndrome but are not it. Leg cramps and positional discomfort — the ordinary numbness or ache from sitting awkwardly — are two mimics named explicitly in the 2014 IRLSSG update; neither shares the worse-at-rest, better-with-movement, worse-at-night pattern that defines RLS.

Restless genital syndrome is a distinct, separately described condition affecting genital rather than leg sensation. It sits outside the evidence base this project draws on, and this page does not attempt to describe, diagnose, or link it to restless legs syndrome. If you notice that specific pattern of symptoms, that is a reason to see a doctor for its own evaluation, not to assume it is restless legs syndrome.

See a doctor if leg restlessness happens regularly, disrupts your sleep, or affects your daytime mood or concentration. Restless legs syndrome is a manageable, well-studied condition, and a proper diagnosis is the first step — not something to defer until it becomes severe.

See a doctor sooner rather than later if you are pregnant (restless legs syndrome is common in pregnancy and has its own management path), if you have kidney disease or anemia (both are recognized secondary causes), or if you notice new symptoms in your arms or trunk while already being treated with a dopamine agonist — a possible sign of augmentation that needs medical review, never a higher dose taken on your own.

A primary care doctor can start the work-up; ongoing or complicated cases are often referred on to a sleep medicine or neurology specialist.