Restless leg syndrome (RLS) flares up in response to a surprisingly wide range of triggers, from common medications and dietary habits to how and when you exercise. Understanding these triggers gives you real leverage over symptom frequency and severity, because many of them are modifiable.
Caffeine, Alcohol, and Nicotine
All three of these substances are recognized aggravators of RLS. The National Institute of Neurological Disorders and Stroke lists reducing or eliminating alcohol, nicotine, and caffeine as a frontline lifestyle change for managing symptoms. Caffeine and nicotine are stimulants that can heighten nervous system arousal during the evening hours when RLS typically peaks. Alcohol, while sedating at first, fragments sleep architecture later in the night, which compounds the sleep disruption RLS already causes.
If you’re not ready to cut these out entirely, pay attention to timing. Consuming any of these in the afternoon or evening is more likely to provoke symptoms than morning use.
Medications That Make RLS Worse
Several common medication classes can trigger or intensify RLS, sometimes catching people off guard because they’re taken for completely unrelated conditions.
Antihistamines are among the top drug classes linked to elevated RLS risk. Diphenhydramine (the active ingredient in many over-the-counter sleep aids and allergy pills) has the strongest evidence. These drugs block a receptor in the brain that normally helps regulate movement-related signaling. When that receptor is blocked, it can disrupt the balance of dopamine activity in areas of the brain that control the urge to move. This disruption can also reduce a calming chemical signal and increase excitatory activity in spinal circuits, reinforcing that uncomfortable need to move your legs. Even newer, “non-drowsy” antihistamines have been implicated in rare cases.
Antidepressants that boost serotonin are another well-known trigger. SSRIs work by increasing serotonin levels, but this comes at a cost: serotonin activity can suppress dopamine production, and dopamine deficiency is central to RLS. Specific medications linked to worsening symptoms include fluoxetine, citalopram, paroxetine, and the older tricyclic amitriptyline. If you notice RLS symptoms starting or getting worse after beginning an antidepressant, that connection is worth raising with your prescriber.
Anti-nausea drugs and antipsychotics that block dopamine receptors directly can also aggravate symptoms, for the same fundamental reason: they reduce dopamine’s ability to do its job in movement-related brain circuits.
Exercise: Helpful or Harmful Depends on How You Do It
Exercise has a complicated relationship with RLS. Consistent, moderate activity generally improves symptoms over time, but the details matter enormously. In a nationwide survey of people with RLS, any abrupt change in exercise routine, whether starting something new, stopping a habit, hiking longer than usual, or pushing harder at the gym, almost always triggered a flare. The key word is consistency. A steady routine, regardless of whether it’s walking, swimming, or stretching, tends to reduce the frequency of symptomatic episodes.
The type and intensity of exercise also play a role. Activities with heavy lower-body involvement, including long walks, jogging, hiking, and cycling at high duration or intensity, were commonly reported to worsen symptoms. Some people found that anything beyond basic stretching would set off a flare.
Timing matters just as much. Over half of survey respondents said morning exercise improved their symptoms, while 56% said afternoon or evening exercise made them worse. If you’re exercising after 4 PM and noticing more restless nights, shifting your workout earlier in the day is one of the simplest changes you can make.
Prolonged Sitting and Inactivity
Long periods of sitting or lying still are classic RLS triggers. Desk work, long flights, car rides, movie theaters: any situation that keeps your legs stationary for extended stretches can bring on symptoms. This is partly why RLS tends to flare in the evening, when people transition from activity to rest. The condition has a circadian component, meaning symptoms naturally peak during the hours you’re winding down and trying to sleep. Prolonged inactivity during the day layers on top of this built-in rhythm.
Low Iron Levels
Iron deficiency is one of the most well-established biological aggravators of RLS. Clinical guidelines recommend checking ferritin, a blood marker of iron stores, in anyone with RLS symptoms. The treatment threshold is a ferritin level at or below 75 mcg/L, which is notably higher than the cutoff used to diagnose general iron deficiency anemia. In other words, your iron stores can be “normal” by standard lab ranges but still low enough to fuel RLS symptoms.
When ferritin falls below 50 mcg/L, oral iron supplementation paired with vitamin C (which helps your body absorb the iron) is typically recommended. This is worth knowing because many people with RLS have never had their ferritin checked, or their levels were dismissed as “fine” based on anemia thresholds rather than the RLS-specific cutoff.
Pregnancy, Especially the Third Trimester
About 29% of pregnant women develop RLS, and the symptoms concentrate heavily in the final months. In one study of 500 pregnant women, 64.4% of those with RLS were in the third trimester, compared to just 4.8% in the first trimester. Symptom severity also peaked in the third trimester. The likely culprits are a combination of dropping iron and folate levels, hormonal shifts, and increased blood volume placing demands on the body’s iron stores. For most women, symptoms resolve after delivery, but the third trimester can be particularly disruptive to sleep.
Kidney Disease
People with end-stage kidney disease have dramatically higher rates of RLS than the general population. While RLS affects roughly 5 to 10% of the general population, studies in dialysis patients have found prevalence rates between 13% and 65%, depending on the adequacy of dialysis and management of anemia. Iron deficiency, anemia, and insufficient dialysis are the main drivers. Women with kidney disease appear to be affected at even higher rates than men in this group.
Sleep Deprivation
Poor sleep and RLS feed each other in a frustrating cycle. Virtually all patients seeking treatment for RLS report disturbed sleep, and the resulting fatigue and sleep debt can, in turn, make the next night’s symptoms worse. People with RLS are more likely to take over 30 minutes to fall asleep, sleep fewer than six hours per night, wake multiple times, and experience unrefreshing sleep. Both insomnia and excessive daytime sleepiness have been identified as significant predictors of RLS symptom presence in large population surveys. Breaking this cycle often requires addressing both the RLS triggers and sleep habits simultaneously.
Warm Temperatures and Seasonal Changes
Heat appears to make RLS worse. A study tracking 64 patients across summer and winter found that symptom severity scores were significantly higher during warmer months. Daytime sleepiness also increased in summer. The effect was most pronounced in men and in patients living in warmer climates (Rome showed strong seasonal variation while Innsbruck, with milder summers, did not). If you notice your symptoms worsening in summer or on hot nights, keeping your bedroom cool and using breathable bedding may help take the edge off.