Restless legs syndrome (RLS, Willis–Ekbom disease) is a neurological disorder with an irresistible urge to move the legs. Unpleasant sensations (crawling, tingling, burning) appear at rest, more often in the evening and at night, and temporarily ease with movement.
One of the key treatable causes of RLS is iron deficiency, so checking ferritin is part of the standard workup.
What it is and how it shows up
RLS disrupts falling asleep and reduces sleep quality, and daytime sleepiness impairs performance and mood. The diagnosis is made clinically from characteristic complaints: an urge to move the legs, worsening at rest and in the evening, relief with movement. Sometimes RLS is secondary — due to pregnancy, kidney disease, or certain medications.
The role of iron deficiency
The brain needs iron to synthesize dopamine, and its shortage in nerve tissue is linked to RLS — even when there is no anemia yet. So in RLS, iron stores are assessed: with low ferritin and reduced transferrin saturation, iron supplements are prescribed. Guidelines suggest considering iron replacement when ferritin is roughly below 75 µg/L.
What to do
Start with lifestyle: a sleep schedule, moderate physical activity, avoiding caffeine, nicotine and alcohol in the second half of the day; where possible, review medications that provoke symptoms. For confirmed iron deficiency — correcting it. If that is not enough, the doctor selects drug therapy.
Calculate using this marker
Calculators where Restless legs syndrome is used directly:
Frequently asked questions
How are restless legs and iron connected?
In RLS, brain iron stores are often reduced, even without anemia. Replenishing iron when ferritin is low often lessens symptoms, so its level is checked in all patients with RLS.
What ferritin is considered low in RLS?
For the brain, a 'sufficient' level is higher than the generally accepted one: iron therapy is usually considered when ferritin is below about 75 µg/L or transferrin saturation is reduced. The doctor makes the decision.