Restless leg syndrome (RLS) has four hallmark features: an urge to move your legs, symptoms that start or worsen during rest, relief with movement, and a pattern of getting worse in the evening or at night. If all four of those apply to you, there’s a strong chance you’re dealing with RLS. About 7% of adults worldwide have it, and it’s more common in women than men.
The Four Signs That Define RLS
RLS isn’t diagnosed with a blood test or imaging scan. It’s identified by a specific pattern of symptoms. All four of the following need to be present:
- An urge to move your legs. This is the core symptom. It’s not just discomfort sitting still. It’s a pulling, nagging drive to get up and move that feels almost impossible to resist.
- Symptoms start or get worse when you’re inactive. Sitting on the couch, lying in bed, riding in a car, or sitting through a long meeting are common triggers. The longer you stay still, the stronger the sensations become.
- Moving brings relief. Walking, stretching, or even just shifting your legs temporarily eases the feeling. The relief usually lasts only as long as you keep moving.
- Symptoms peak in the evening or at night. RLS follows a clear circadian pattern. You might feel perfectly fine during the morning and afternoon, then notice the sensations creeping in after dinner or when you get into bed.
That evening timing is one of the most distinguishing features. It’s what separates RLS from many other leg conditions. The nighttime worsening also explains why RLS so heavily disrupts sleep, which in turn affects mood, energy, and daytime functioning.
What RLS Actually Feels Like
One of the reasons RLS goes unrecognized is that the sensation is genuinely hard to describe. People use words like creeping, crawling, tingling, pulling, itching, or a “creepy-crawly” feeling deep inside their legs. Some describe it as an electric buzzing or a feeling like something is moving under their skin. Others say it’s not exactly painful but deeply uncomfortable in a way that’s hard to put into words.
The sensations usually occur deep in the legs, not on the surface of the skin. They’re most common in the calves but can affect the thighs, feet, or even the arms. What makes RLS distinct from ordinary restlessness is that the urge to move feels involuntary. It’s not that you’re bored and fidgety. It’s that your body is generating a signal you can’t ignore.
Conditions That Look Like RLS but Aren’t
Several other problems can cause leg discomfort at night, and telling them apart matters because the treatments are different.
Nighttime leg cramps are the most common lookalike. Like RLS, they can follow a nighttime pattern and happen at rest. But cramps involve a sudden, painful muscle contraction you can actually feel as a hard knot. RLS doesn’t produce that kind of visible muscle tightening.
Nerve damage (peripheral neuropathy) causes tingling, numbness, or burning that can sound similar to RLS descriptions. The key differences: neuropathy symptoms don’t improve with movement, they aren’t accompanied by a restless urge to move, and they don’t follow the evening pattern.
Circulation problems like blood clots or narrowed arteries also cause leg discomfort. But vascular issues typically get worse with activity (walking uphill, for example) and better with rest, which is the opposite of RLS. They may also involve swelling, cool skin, or weak pulses in the feet.
If your symptoms don’t clearly match the four-feature pattern described above, or if they’re accompanied by visible swelling, skin changes, or numbness that doesn’t go away, something other than RLS may be responsible.
Who Gets RLS and Why
RLS affects roughly 7% of adults between ages 20 and 79. Women are affected at higher rates than men, with prevalence around 8.3% for women compared to 6% for men. It can start at any age, though many people notice it worsening in middle age.
The strongest known contributor is low iron availability in the brain. Your blood iron levels might even appear “normal” on a standard test, but RLS specialists use a stricter threshold. If your stored iron (ferritin) is at or below 75, that’s considered low enough to potentially drive RLS symptoms, even though most labs flag ferritin as abnormal only below 10 or 20. This is why a ferritin blood test is one of the first things a doctor will order if you describe RLS symptoms.
Genetics also play a significant role. RLS runs in families, and having a first-degree relative with it increases your risk substantially.
RLS During Pregnancy
About 14% of pregnant women develop RLS, making pregnancy one of the most common triggers. The condition typically appears in the second or third trimester and often resolves after delivery.
Low hemoglobin is a major factor. Pregnant women with low hemoglobin levels are about 1.7 times more likely to develop RLS. On the flip side, women who take preventive iron supplements during pregnancy are roughly 41% less likely to develop it. Women who’ve had RLS before pregnancy are at especially high risk of recurrence, with odds more than seven times higher than those with no history.
Preeclampsia also raises the risk, approximately doubling the odds. If you’re pregnant and noticing restless, uncomfortable legs that worsen at bedtime, it’s worth mentioning to your provider, both because treatment options exist and because it may flag low iron that’s worth addressing on its own.
Getting a Diagnosis
There’s no single test that confirms RLS. A doctor will ask you to describe your symptoms in your own words, paying attention to the four key features: the urge to move, worsening at rest, relief with movement, and evening timing. Be specific about when it happens and what it feels like. Using descriptors like “crawling,” “pulling,” or “can’t keep my legs still” helps communicate what you’re experiencing.
Blood work typically follows, with ferritin being the most important test. If your ferritin is below 75, iron supplementation alone sometimes reduces or eliminates symptoms. Your doctor may also evaluate for other conditions that can trigger or worsen RLS, including kidney disease, thyroid problems, and certain medications (some antidepressants and antihistamines can intensify symptoms).
Many people live with RLS for years before bringing it up because it sounds minor or hard to explain. If you’re losing sleep several nights a week because of an irresistible need to move your legs, that’s not trivial, and it’s a recognized medical condition with effective treatments.
What Helps
For mild RLS, lifestyle changes can make a noticeable difference. Regular moderate exercise (but not intense workouts close to bedtime), reducing caffeine and alcohol, and maintaining a consistent sleep schedule all help some people. Leg massage, warm baths, or heating pads before bed provide temporary relief for many.
If your ferritin level is low, iron supplementation is the first-line approach. Taking iron every other day on an empty stomach, paired with vitamin C to improve absorption, is the typical recommendation. It can take several weeks to notice improvement because iron stores build gradually.
For moderate to severe RLS that doesn’t respond to iron, prescription medications targeting the nervous system can significantly reduce symptoms. These work by influencing how your brain processes the signals that create the urge to move. The right choice depends on how frequent and severe your symptoms are, so this is a conversation to have with a provider who understands the condition well.