You know the night when sleep simply will not come. You lie down. Your body feels tired, yet something restless keeps pulling you back from the edge of sleep. For a lot of people, the problem is not insomnia at all.
Restless legs syndrome (RLS) affects an estimated 7 to 10 percent of the US population, according to the National Institute of Neurological Disorders and Stroke.
RLS is widely underdiagnosed. Many patients are treated for sleep problems or anxiety for years before the right diagnosis is finally made.
The confusion makes sense. The symptoms appear at bedtime, so the first guess is a sleep disorder. But RLS is a nerve-and-movement condition with a very specific fingerprint. Once you know the pattern, it is hard to miss.
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The eight signs that set RLS apart
Doctors look for a cluster of signs, not one alone. According to the NINDS and the Mayo Clinic, these are the features that point to restless legs syndrome.
- An urge to move the legs that is hard to resist. It builds up when you are still and eases only when you move.
- Crawling, creeping or tingling sensations deep in the legs. Some people describe it as throbbing, aching or an electric feeling. It sits inside the leg, not on the skin.
- Symptoms that start or get worse when you rest. Lying down or sitting quietly brings them on, even when you are not yet tired.
- A clear evening and night pattern. The feelings peak after dark and ease in the morning hours.
- Fast relief from walking or stretching. Pacing, jiggling the legs or getting up usually calms things down almost immediately.
- Involuntary leg jerks during sleep. Most people with RLS also have periodic limb movements of sleep, brief, repeating twitches or kicks that disturb rest without waking the sleeper fully.
- Daytime fatigue, poor concentration and irritability. Broken sleep leaves a mark the next day. That mark is often what finally sends people to a doctor.
- Worsening during long sitting or in pregnancy. Long flights, car rides and movie theaters tend to trigger symptoms. Many women first notice RLS during the last trimester of pregnancy.
Why pregnancy and iron matter
Low iron in the brain is one of the strongest biological threads in RLS. A clinical review in Mayo Clinic Proceedings describes brain iron deficiency as a key biological driver of the condition.
Ordinary iron deficiency is also one of the most common partner diagnoses. That is why pregnancy, when iron stores drop sharply, is such a classic trigger.
Women who develop restless legs in late pregnancy face other health risks worth flagging to a doctor as well.
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What to do when the pattern fits
There is no single blood test or scan that proves RLS. Diagnosis rests on the symptoms themselves.
Mayo Clinic specialists recommend a serum ferritin blood test as the first step. Raising a low iron level can ease symptoms for many patients. When iron is not the answer, prescription medicines for RLS are available and often effective.
If the symptoms above line up with your nights, ask your doctor specifically about restless legs syndrome rather than insomnia. A serum ferritin blood test is usually where the workup begins.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.