All You Need to Know About Restless Leg Syndrome
The poorly understood sensations of “pins and needles,” “creepy crawlies,” or “itchiness” affect women twice as much as men.
Restless leg syndrome (RLS) sounds commonplace — who hasn’t felt the need to get up and stretch their legs now and then? While the syndrome is much more than that, and also rarer, the good news is it is benign and people who have RLS can typically manage the syndrome through self-care and lifestyle changes.
But the condition is often overlooked, shrugged off or misdiagnosed. If the condition is mild, this is generally not a problem. But undiagnosed and/or unmanaged moderate-to-severe restless leg syndrome can cause serious sleep disruptions. And regardless of intensity, research has linked the condition — also known as Willis-Ekbom disease — to other, more serious health issues.
What is restless leg syndrome?
Restless leg syndrome is a nervous system disorder that’s exactly what it sounds like — an uncontrollable need to move one’s legs to get rid of an uncomfortable sensation, which typically eases upon movement. It’s a chronic condition that is rare. While the condition has not been studied much in India, one small-scale research project estimated a prevalence of 2.1% among Bengaluru residents. One 2012 meta-analysis of restless leg syndrome determined the condition affects anywhere from 1.9% to 4.6% of people globally when other conditions and medications with similar symptoms or side effects were ruled out.
What causes restless leg syndrome?
Medical science still has a limited understanding of RLS; not enough research into RLS exists yet to draw hard-and-fast conclusions. In other words, there’s no known cause for RLS, though experts do say a genetic factor is likely, given that RLS tends to run in families; research has also revealed that the functional quirks of several genes are related to the condition.
That said — two major, interrelated hypotheses about the cause of RLS are gaining credence. One theory is that low levels of iron in the brain — which may or may not reflect in blood tests of iron levels — may prompt RLS. Research on brain tissue donated by deceased RLS patients has revealed iron deficiency and reduced iron storage capacity in the substantia nigra, a part of the brain where dopamine is produced, according to the Department of Neurology and Neurosurgery at Johns Hopkins Medicine.
Which brings us to the second, related hypothesis: impaired dopamine function. Dopamine is a brain chemical that acts as a messenger to nerves that regulate movement, among other things. Similar studies of donated tissue have found RLS patients’ brains contain unusually low amounts of dopamine receptors and unusually high amounts of dopamine-producing proteins. “If a cell cannot ‘hear’ the dopamine message from another cell, it ‘tells’ the other cell to ‘turn up’ the dopamine.
Thus Despite the increase in dopamine, the end result may be a decrease in the effect that dopamine has on certain brains [sic] cells,” and this, potentially, a sensation that prompts irresistible movement, according to the Department of Neurology and Neurosurgery at Johns Hopkins Medicine. The fact that our bodies’ dopamine levels naturally drop as the day progresses also supports this theory, as RLS symptoms tend to worsen in the evening and at night.
That said, RLS can also be a side effect of medications or other conditions. However, it’s not clear whether these prompt the underlying iron-dopamine issues and thus RLS, or other, unknown biological mechanisms that could underlie the syndrome. Pregnancy, for instance, is a major cause of RLS; the hormonal fluctuations of pregnancy can either worsen symptoms in someone who already has RLS or cause the development of RLS in someone who has never experienced the syndrome before. Pregnancy-induced RLS typically develops during the third trimester and resolves within a few months of birth — though women who develop RLS during pregnancy are more likely than the general population to develop ongoing RLS. Other related, contributing conditions include a diagnosed iron deficiency, nerve and/or spinal cord damage, chronic kidney disease, diabetes, Parkinson’s disease, rheumatoid arthritis, hypothyroidism, or fibromyalgia, according to multiple medical sources.
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What are the symptoms of restless leg syndrome?
People with restless leg syndrome often describe an “itchy,” “pins and needles,” or “creepy-crawly” sensation in their legs, prompting them to need to stretch, jiggle, walk or otherwise move their legs in order to dispel the discomfort, according to multiple medical sources. These sensations, which may also include throbbing, aching, pulling, or an electric-shock feeling, often set in after sitting or lying down for a period of time, and are most common in the evening. People with RLS typically experience these sensations in both legs; more rarely, they may experience the feelings in their arms.
These symptoms may occur regularly, or they may come and go. They also may vary in severity.
Restless leg syndrome is also characterized by nighttime leg twitching, which according to the Mayo Clinic “may be associated with another, more common condition called periodic limb movement of sleep, which causes your legs to twitch and kick, possibly throughout the night, while you sleep.” This is where restless leg syndrome can take a turn from benign-but-annoying to benign-but-severely-affecting-one’s-quality-of-life, as nighttime leg twitching can diminish the amount and quality of one’s sleep.
Who is at risk for restless leg syndrome?
Anyone — adult or child — can develop restless leg syndrome at any time. That said, the syndrome is roughly twice as common among women as it is among men, according to the 2012 analysis. It also becomes more common as age increases.
People with a family member who has restless leg syndrome are also more prone to develop the condition themselves, according to the Mayo Clinic.
And people who become pregnant and/or who have one of the related, contributing conditions listed above are more at risk for RLS.
Does restless leg syndrome carry any risks?
It’s difficult to say. Research has linked the syndrome with other health issues, but has yet to prove conclusively one leads to the other. For instance, some research has associated RLS with a higher chance of mortality; other research, seeking to explain this, has found people with RLS are at greater risk for cardiovascular disease (but the association weakens when RLS symptoms are less frequent). In any case, it’s unclear whether RLS plays a role in this increased risk, or related underlying conditions; for instance, diabetes is a condition linked to increased risk of RLS as well as cardiovascular disease.
Still other research has linked RLS with depression; one recent study, published in the Journal of the American Medical Association, found people with restless leg syndrome were nearly three times as likely to attempt self-harm or suicide as the general population. But it’s unclear whether this is because of a physiological reason, or merely the effect of living with a difficult, poorly understood condition associated with impaired sleep; according to the Mayo Clinic, severe RLS “can cause marked impairment in life quality and can result in depression” and “some people with [RLS] never seek medical attention because they worry they won’t be taken seriously.”
Much more research remains to be done to confirm and clarify the relationship between RLS and its related conditions.
How is restless leg syndrome diagnosed?
Restless leg syndrome is often mistaken for other conditions or side effects. For children, particularly, RLS is often mistaken for ADHD.
But per the Mayo Clinic, the diagnosis of restless leg syndrome relies on five points:
- Uncomfortable sensations in the legs that irresistibly prompts you to move your legs.
- Symptoms are relieved, at least in part, by the movement.
- Symptoms begin or worsen when sitting or lying.
- Symptoms worsen at night.
- Symptoms can’t be explained by another condition.
A doctor may also take a family history and/or order a variety of tests to rule out other conditions. They also may refer you for a sleep study or ask you to keep a sleep diary, though this is not included in diagnostic criteria.
Is restless leg syndrome curable?
Potentially. Sometimes, resolving an underlying cause of RLS — for instance, after childbirth, as in the case of pregnancy onset, or if an iron deficiency is balanced — can cure people of the syndrome.
For many, however, RLS is a chronic condition. However, lifestyle changes around exercise, diet, weight, sleep habits, and stress management may ease symptoms. Leg massages and/or applying heat or cold to the affected limbs are also recommended.
Some medications may help ease RLS symptoms. For instance, drugs that stimulate the dopamine system have been shown to reduce RLS symptoms. Iron supplementation, in the case of iron deficiency, has also improved RLS symptoms, according to the Department of Neurology and Neurosurgery at Johns Hopkins Medicine.
For some, it may be helpful to stop or curtail medications linked to RLS onset, such as some antidepressants, antipsychotics, lithium, calcium-channel blockers, antihistamines and nausea medications, according to the U.K’s NHS. However, this should only be done under the guidance of the prescribing doctor.
Ultimately, all experts advise consulting a doctor, regardless of how severe one’s symptoms are, who can help manage symptoms and improve one’s quality of life.
Liesl Goecker is The Swaddle's managing editor.