Quick version
Restless Legs Syndrome (RLS) is a neurological condition that causes a strong urge to move the legs when resting, especially during the evenings and nights. It is often caused by disturbances in the brain's iron balance, which makes tests of the body's iron stores (ferritin and transferrin saturation) central to the investigation. Treatment is tailored to the cause and severity – from lifestyle changes and targeted iron therapy (where IV iron is the first choice for ferritin between 75–100 ng/ml) to modern drugs that affect calcium channels.
Do you recognize the feeling of being completely exhausted, lying in bed – and just then your legs start to “crawl”, pull, tingle or feel impossible to keep still? Restless legs, or restless legs syndrome (RLS), is common and can affect both sleep, energy, mood and work capacity. For many, it is not just about “ants in the legs”, but about a clear neurological disorder where there is a strong impulse to move the legs, especially in the evening and at night. There are often also possible underlying causes and treatment to consider, not least iron deficiency.
What are restless legs and how does it feel?
Restless legs syndrome is a neurological condition characterized by a strong, irresistible desire to move the legs, often together with unpleasant sensations. The symptoms typically occur when you are resting, for example when you are sitting still on the couch, driving a car, sitting in a meeting or trying to fall asleep. Movement often provides at least temporary relief, and symptoms are usually most pronounced in the evening or at night.
Common descriptions include:
- creeping or tingling sensations in the legs
- drawings, tingling or internal “restlessness”
- a discomfort that is difficult to describe but which makes you have to move
- difficulty sleeping because the symptoms worsen when you lie still
It is important to distinguish restless legs from other leg disorders. Muscle cramps, nerve damage, vascular problems and general anxiety in the body can cause similar symptoms, but do not always follow the same pattern of worsening at rest, relief from movement and clear evening or nighttime worsening. The diagnosis is made primarily based on the medical history and symptoms, not through a single X-ray or a specific laboratory test. However, blood tests are often important in finding underlying causes.
Restless legs do not necessarily involve pain. Many people experience a vague discomfort, tingling or a deep feeling of restlessness rather than pure pain, although pain occurs in some cases. The condition itself is harmless, but the impact on everyday life can still be significant. When a night's sleep and recovery are not achieved, the long-term lack of sleep risks having a severe impact on concentration, mood, blood pressure and general performance.
What underlying causes can be found in restless legs?
In some people, there is no clear single explanation, but several conditions are well known to be able to trigger or worsen restless legs. The most important thing to know is iron deficiency, even when the blood value is not significantly reduced. In restless legs, therefore, one looks not only at hemoglobin but also at the body's iron stores, especially ferritin and transferrin saturation. Patients with clinically significant restless legs should be regularly assessed with iron status.
Common underlying or contributing factors are:
- Iron deficiency or low iron stores
- Pregnancy, especially in the latter part of pregnancy
- Chronic kidney disease
- Peripheral neuropathy, i.e. nerve damage in, for example, the feet and legs
- Heredity or genetic predisposition
- Insomnia or other concomitant sleep disorder, such as obstructive sleep apnea
- Certain medications that can worsen the symptoms
Iron plays a particularly important role because the brain's iron balance seems to be important for the nerve signals that control movement and sensations. One can therefore have troublesome restless legs even though regular blood tests look "almost normal". Therefore, the assessment needs to be more nuanced than just checking the blood value. Iron therapy should be considered if ferritin is below 75 ng/ml or transferrin saturation is below 20%. If ferritin is between 75 and 100 ng/ml, intravenous iron is the first-line treatment, since in this range the body often has difficulty absorbing oral iron in sufficient quantities to reach the brain.
Pregnancy is also a common situation. Many people experience their first symptoms during pregnancy, often in the third trimester. The symptoms often go away after childbirth, but still need to be taken seriously because lack of sleep during pregnancy can be very stressful. During pregnancy, you must also be extra careful with the choice of medication, which makes investigating, for example, iron deficiency even more important.
What medications and habits can worsen the symptoms?
An important part of treatment is identifying things that make restless legs worse. According to current guidelines, the first step should be to review aggravating factors such as alcohol, caffeine, certain medications, and untreated sleep apnea.
Examples of things that can worsen symptoms include:
- caffeine, especially late in the day
- alcohol
- sleep deprivation
- certain antihistamines, especially sedatives for allergies or colds
- certain antidepressants
- certain antipsychotic medications
- certain anti-nausea medications that affect the dopamine system
This does not mean that you should stop taking prescribed medications yourself, but it is wise to discuss with your doctor if your symptoms have worsened after starting a new medication. Sometimes it is possible to change the medication, adjust the dose or treat restless legs more specifically.
Common self-care advice that can help, especially with milder symptoms, is:
- regular sleep habits
- moderate physical activity
- stretching or light massage in the evening
- avoiding prolonged sitting
- reducing caffeine and alcohol, especially in the evening
- treating a concomitant sleep disorder if any
Many people try magnesium and some experience some subjective relief, but the supplement lacks support in the guidelines and is not an established first-line treatment for restless legs. If the underlying problem is due to iron deficiency, a sleep disorder or medication side effects, investigating and treating the actual cause is much more effective than taking dietary supplements at random.
How is restless legs treated in practice?
Treatment is guided by the cause, severity and life situation. If restless legs are due to an underlying factor, such as iron deficiency, this is often where to start. In many cases, symptoms improve significantly when the iron deficiency is corrected. Treatment is given either as tablets or via intravenous infusion (IV iron). Intravenous iron is the first-line treatment when ferritin is between 75 and 100 ng/ml, since the absorption of tablets in the intestine in this range is too low to raise iron levels in the brain. Iron should not be treated casually, but testing and follow-up are important.
If lifestyle measures and treatment of underlying causes are not enough, medication may be considered. Drugs that affect calcium channels – such as gabapentin, gabapentin enacarbil and pregabalin – are the first choice for many patients, with gabapentin enacarbil being strongly recommended.
Dopaminergic drugs, such as pramipexole, ropinirole and rotigotine, were used more often in the past but are now used more selectively. The reason is that in some patients they can cause augmentation, which means that symptoms worsen over time, occur earlier in the day or spread to other parts of the body such as the arms. This is a central reason why modern treatment primarily prioritizes other alternatives.
In severe and therapy-resistant conditions, other treatments may also be considered in specialist care. But for most people, the most important thing is to:
- confirm that it is indeed restless legs
- look for treatable causes
- review medications and lifestyle factors
- choose treatment based on the severity of the symptoms and the individual's risk profile
For those wondering "do I have to live with this?" the answer is often no. Many people experience clear improvement when the correct cause is identified and the treatment is adjusted correctly from the start.
When should you test your values for restless legs?
It is wise to consider testing if you have recurring symptoms in the evening or at night, especially if you also have fatigue, sleep problems or belong to a group where iron deficiency is more common. This applies, for example, to:
- pregnancy or postpartum
- heavy menstruation
- vegetarian or vegan diet with risk of low iron intake
- known kidney disease
- long-term fatigue or reduced energy
- restless legs that have worsened over time
During the investigation, it is often relevant to check:
- ferritin
- iron and transferrin saturation
- sometimes also blood status, kidney values and other tests depending on symptoms and medical history
This is particularly important because a person may be told that “the blood values look normal” even though the iron stores are still too low to be optimal for restless legs. That is why health checks and targeted sampling can provide valuable information – both for private individuals who want to understand their sleep and energy, and for companies that want to work preventively with employee health.
