Restless legs syndrome: symptoms, causes and treatment

People describe the sensations in many ways. NHS inform lists tingling, burning, itching or throbbing, a creepy-crawly feeling, a sense of fizzy water in the blood vessels, and a painful cramping sensation in the calves. Movement or rubbing the legs usually gives relief, and symptoms can range from mild to severe. The arms, chest and face can occasionally be involved.

Sitting still for a long time, such as on a train or at the cinema, can be difficult. NHS inform also says up to 80% of people with RLS have periodic limb movements in sleep, brief repeated jerks or twitches of the legs usually every 10 to 60 seconds, which can wake both the person and their partner.

The NHS notes that leg cramps and peripheral neuropathy can cause similar symptoms, which is one reason the pattern matters.

• An urge to move the legs, often with an unpleasant feeling.

• Symptoms begin or worsen when resting, such as lying down or sitting.

• Movement, such as walking or stretching, gives partial or total relief while it lasts.

• Symptoms are worse, or occur only, in the evening or at night.

Most RLS has no clear cause, and NICE CKS calls it frequently idiopathic. It may be secondary to another condition, most commonly pregnancy, iron deficiency or stage 5 chronic kidney disease, or to certain medicines. NHS inform adds diabetes, Parkinson's disease, rheumatoid arthritis, an underactive thyroid and fibromyalgia as conditions that can lead to secondary RLS.

Some medicines can worsen symptoms without causing the condition. NHS inform lists some antidepressants, antipsychotics, lithium, calcium channel blockers, some antihistamines and metoclopramide. It stresses that nobody should stop a prescribed medicine without checking with their GP first. Smoking, too much caffeine or alcohol, being overweight, stress and lack of exercise can act as triggers.

NHS inform explains that dopamine levels naturally fall towards the end of the day, which may explain why symptoms are often worse in the evening and night.

RLS is a disorder of the nervous system. NICE Clinical Knowledge Summaries describes it as an irresistible urge to move the limbs, usually the legs, accompanied by uncomfortable sensations. The urge is typically worse in the evening and often goes with disturbed sleep. The underlying mechanism is not fully understood, although it is likely that the dopamine system is involved.

Because it so often interferes with sleep, RLS-UK, a charity, notes that it is also considered a sleep disorder. It may start at any age, including childhood. For some people it is progressive, while in others symptoms come and go.

There is no single test. NHS inform says diagnosis rests on symptoms, medical and family history, examination and test results, and a GP should be able to make it. NICE CKS lists the criteria that must all be present: the urge to move, onset or worsening at rest, relief with movement, an evening or night pattern, and no better explanation such as leg cramps or habitual foot tapping.

Blood tests look for causes rather than confirm RLS. NICE CKS names serum ferritin to identify iron deficiency, with renal function, full blood count, thyroid function, blood glucose and vitamin B12 as guided by the history. If sleep is badly disrupted, NHS inform says sleep tests may be arranged. NICE CKS suggests referral to a neurologist or sleep specialist when the diagnosis is uncertain or first treatment fails.

Treatment depends on the cause and severity. If another condition is responsible, treating it may help. The NHS gives the example of iron supplements for low iron, and says a doctor may check other medicines for ones that worsen RLS. NICE CKS says that for moderate to severe symptoms an alpha-2-delta ligand such as pregabalin or gabapentin, used off-label, is an option, and that a short or intermittent hypnotic may be considered when sleep disturbance is significant.

The NHS also lists painkillers such as codeine or tramadol in some cases, and medicines that increase dopamine, such as co-careldopa or ropinirole, for occasional use or if other medicines have not worked. NHS inform warns that dopamine agonists can cause impulse control disorders and augmentation, which makes RLS worse. RLS-UK urges anyone taking ropinirole, pramipexole or rotigotine to read its guidance on augmentation, and says a review of warnings has been prompted by reports of impulse control problems.

Never change or stop these medicines on your own. If symptoms do not improve, the NHS says you may be referred to a specialist.

For mild symptoms, explanation, reassurance and self-help may be enough, according to NICE CKS. The NHS suggests exercising during the day, going to bed and waking at the same times, keeping the bedroom dark and quiet, a warm bath or heat pads before bed, and walking, stretching or massaging the legs when symptoms strike. It also lists distraction with a puzzle or book, and help to stop smoking.

The NHS advises avoiding caffeine after midday, alcohol for at least 2 hours before bed, big meals or strenuous exercise late at night, phones and screens right before bed, and daytime naps. NHS inform adds hot or cold compresses and relaxation exercises such as yoga or tai chi as ways to relieve an episode.

RLS is not life threatening, as NHS inform notes, but severe cases can cause insomnia and trigger anxiety and depression. The NHS advises seeing a GP if symptoms stop you sleeping, affect your mental health, or have not improved with self-help. If low mood is part of the picture, talking therapies may help.

NICE CKS says that in idiopathic RLS the severity and frequency of symptoms typically increase over time, so a periodic review of treatment is sensible. Private neurology and sleep services are available and use the same assessment steps, but a GP review and a ferritin result usually come first.