Restless legs syndrome: the urge to move, why it peaks at night, and what actually helps

Restless legs syndrome, now also called Willis-Ekbom disease, is a sensorimotor disorder defined by an overwhelming urge to move the legs, usually accompanied by uncomfortable sensations that people describe as crawling, creeping, pulling, tugging, or an electric ache deep in the limb. The International Restless Legs Syndrome Study Group set out five essential features, updated by Richard Allen and colleagues in Sleep Medicine in 2014: the urge to move, worse at rest, relieved by movement, worse in the evening or night, and not better explained by another condition such as leg cramps or positional discomfort. The relief with movement is the giveaway, and it is temporary, so the legs pull the person to keep moving, pace, or stretch. It is common, affecting a meaningful percentage of adults, more women than men, and it ranges from an occasional nuisance to a nightly ordeal that dominates the evening and wrecks sleep. It is a clinical diagnosis made from that pattern, not from a scan or a blood test.

The feature that ties restless legs to a circadian site is that the symptoms are not merely triggered by lying down; they follow the body clock. Studies of RLS severity across the day, including work by Claudia Trenkwalder and colleagues, show the discomfort and the involuntary leg movements peak in the late evening and the first part of the night and are lowest in the morning, and this rhythm persists even when researchers hold posture and activity constant, which means it is genuinely circadian rather than just a consequence of resting in bed. The leading explanation links this to the daily rhythm of the dopamine system, which has its own circadian variation with lower dopaminergic tone at night, exactly when RLS is worst. That timing is why RLS is so destructive to sleep specifically: the symptoms crest right at the hours when a person is trying to fall asleep and stay asleep, turning sleep onset into a fight and fragmenting the night with the urge to move.

The best-supported model of restless legs joins two threads, brain iron and dopamine, and they are connected. Iron is a required cofactor for the enzyme that makes dopamine, and imaging and autopsy work led by researchers including Richard Allen and Christopher Earley points to reduced iron in specific brain regions in people with RLS even when their blood iron looks normal, alongside a dysfunctional dopamine system. This is why low iron stores make RLS worse and why correcting them can help: iron is upstream of the dopamine pathway that the disorder disrupts. Genetics load the dice too; large studies have identified common variants, in genes such as BTBD9 and MEIS1, that raise risk and that also relate to iron handling, which is why RLS so often runs in families and appears early in life in those cases. The practical upshot of the model is direct: check and correct iron first, and understand that the dopamine angle explains both the nighttime timing and why dopamine drugs can help in the short term while causing trouble over the long term.

Several common factors aggravate restless legs, and spotting them is often the highest-yield step. Iron deficiency is the big one, and it does not require anemia; a low ferritin with normal hemoglobin is enough, which is why the iron check matters even in people who feel otherwise well. Pregnancy, especially the third trimester, provokes or worsens RLS in a large minority of women, usually easing after delivery, and advanced kidney disease on dialysis is another strong secondary cause. Medications are a frequently missed driver: sedating antihistamines (including some over-the-counter sleep aids), many antidepressants that act on serotonin, and antidopaminergic anti-nausea drugs such as metoclopramide can all unmask or intensify symptoms. Everyday inputs matter too, with caffeine, nicotine, and alcohol commonly reported to worsen the evening restlessness. Because so many of these are reversible, a careful review of iron status and the medication list is worth more than any supplement.

Treatment follows the model. The first move is to fix reversible causes: correct low iron stores under medical guidance, since iron repletion (oral or, when needed, intravenous) can substantially reduce symptoms when ferritin is low, and remove or swap the aggravating medications and evening stimulants where possible. For milder cases, movement, stretching, and steady sleep timing that respects the circadian pattern can be enough. When symptoms are persistent and troublesome, the American Academy of Neurology guideline led by John Winkelman in 2016 and later expert consensus have shifted first-line drug therapy toward the alpha-2-delta ligands, gabapentin enacarbil, gabapentin, and pregabalin, which reduce symptoms without the augmentation problem that plagues the older dopamine agonists. Dopamine agonists still work quickly but are increasingly held back because of that long-term risk. The right choice depends on the individual, coexisting pain or anxiety, and other conditions, so this is a decision to make with a clinician rather than by self-prescription.

The most important pitfall in restless legs treatment has a name: augmentation. When RLS is treated long-term with a dopamine agonist, the drug can paradoxically make the disorder worse over months to years, so symptoms start earlier in the day, become more intense, spread from the legs to the arms or trunk, and respond less to each dose. The instinctive response, raising the dose, accelerates the problem, which is exactly why guidelines now steer away from agonists as a default and why anyone on one whose symptoms are creeping earlier in the day should see their prescriber rather than increase the dose. More broadly, restless legs is worth a medical evaluation rather than self-management: to confirm the diagnosis and separate it from cramps, neuropathy, or positional discomfort, to check ferritin and screen for secondary causes such as iron deficiency, pregnancy, or kidney disease, and to choose treatment sensibly. Sudden severe symptoms, or leg discomfort with swelling, weakness, or numbness, point elsewhere and need assessment. This article is educational and not medical advice.