The symptoms of restless legs syndrome sound like the plot of a horror movie. If you have this condition, you might sink into bed at the end of each day aching for a good night’s sleep. Then itbegins. An irresistible urge to move your legs won’t allow you any peace. You feel creeping, crawling, tingling, aching, or twitching sensations in your lower extremities, making it almost impossible to sleep. If you don’t have restless legs syndrome (RLS for short), this may sound unimaginable. But for people with intense cases of RLS, this might be just another typical night.
In 1685, a doctor named Sir Thomas Willis recorded the first written case about RLS, according to a 2012 review in Sleep Medicine Reviews. Fast forward to 1945, when a doctor named Karl-Axel Ekbom came up with the name “Restless-Legs Syndrome.” Though both milestones happened some time ago, doctors are still searching for a definitive cause and cure for this condition, alternatively called Willis-Ekbom disease. Here are nine facts explaining what doctors know so far about this baffling disorder and which mysteries still need investigating.
1. Restless legs syndrome causes unusual physical sensations and movement.
RLS is a neurological disorder involving a powerful impulse to move body parts, usually because of uncomfortable sensations, according to the National Institute of Neurological Disorders and Stroke (NINDS). Although this condition nearly always affects the legs—they’re right there in the name, after all—it’s also possible for RLS to affect areas like the arms, chest, and head, according to the NINDS.
Sometimes RLS sensations are so weird that people have trouble describing them, according to the Mayo Clinic. With that said, the following descriptions are generally agreed upon to come pretty close:
- Electric feelings
These symptoms may affect up to 7 to 10 percent of people in the United States, according to NINDS estimates. It can begin at any age, but RLS becomes more common as people get older, the Mayo Clinic says. If symptoms start before age 40, it’s more likely that there’s a genetic component involved (more on that later).
It’s possible to experience these symptoms at varying levels of severity every night, a few times a week, or even less often than that, according to the NINDS. However, RLS typically becomes more frequent and severe with age.
2. Moving the legs can temporarily tame these odd feelings.
It’s only natural that if you have an uncontrollable urge to move your legs, you’re going to do just that. Interestingly enough, moving the body parts affected by RLS can get rid of or lessen the symptoms temporarily, according to the Mayo Clinic.
This is why many people with RLS will do things like pace, tap their feet, stretch, and generally move their legs as much as possible when they have symptoms. But the sensations return once the motion stops, which is a huge reason why this condition can be so life-disrupting depending on its severity.
3. RLS can make it almost impossible to sleep well.
In a cruel twist, symptoms are most likely to strike when you’re most desperate for rest: as you try to go to sleep. Since most people work during the day and sleep at night, symptoms tend to arise in the late afternoon and evening, becoming exacerbated at night when a person is at rest, the NINDSexplains. (This is because RLS appears to follow a person’s circadian rhythm.)
As such, RLS can lead to issues like excessive daytime sleepiness that can put stress on relationships and work. It can also harm mental health. Feelings of frustration and helplessness are only to be expected when your own body robs you of sleep, and that can eventually contribute to conditions such as depression and anxiety.
This chronic lack of sleep is part of why there’s fervent interest around whether or not RLS may increase the risk of physical health issues such as cardiovascular disease. Although the existence of an association is still up for debate, some researchers believe that the connection lies, at least in part, in a lack of sleep. (This could be due to a constellation of factors, like how a lack of sleep is a risk factor for obesity, which can then contribute to heart disease.)
4. RLS can cause another sensory issue called periodic limb movements of sleep.
In addition to the (sometimes literal) pain of falling asleep, it’s estimated that more than 80 percent of individuals with RLS also experience periodic limb movements of sleep (PLMS), the NINDSsays. These are basically involuntary leg and/or arm spasms that can happen as often as every 15 to 40 seconds all night long, causing constant disruptions that might further harm your sleep.
It appears as though blood pressure and heart rate spike temporarily during these jerky movements, which is why some experts posit that PLMS and, relatedly, RLS may raise a person’s risk of heart issues over time.