What is restless legs syndrome?
Restless leg syndrome, also known as Willis-Ekbom disease, is a condition of the nervous system that causes the sufferer to have an overwhelming urge to move their legs. This is typically accompanied by an uncomfortable ‘creeping’ sensation in the feet, calves and thighs.
Restless leg syndrome is relatively common, with between 2 and 5 adults in every 100 having experienced some form of the condition in their life. It can affect anyone and can develop at any age, although it is more common as you get older and women are twice as likely to be affected as men.
Symptoms of restless leg syndrome
Sufferers of restless leg syndrome often struggle to explain the sensation, but it has been described as an ‘itching or tickling in the muscles like an itch that you can’t scratch’, a creepy-crawly feeling, or as if you have fizzy water inside your legs. You feel like you want to move, massage or stretch your legs to relieve the symptoms, although this only reduces the feelings for a few seconds before they return.
Symptoms of restless leg syndrome often worsen at night when in a relaxed state, or in a confined space such as a car, airplane or cinema. It is a condition that is considered a sleep disorder as symptoms increase in severity at night, making it difficult to fall asleep. Those who suffer from the condition may experience less than 5 hours sleep a night and even those with more of a mild form will see their quality of sleep reduce, which can lead to symptoms of sleep deprivation in day-to-day life.
Restless leg syndrome is often associated with Periodic Limb Movements in Sleep (PLMS) which is an involuntary movement of the arms and legs during sleep, which you often have no control over. It can occur every 15-40 seconds, sometimes lasting throughout the night. Over 80% of people with restless leg syndrome also suffer with PLMS, although most people with PLMS do not experience restless leg syndrome.
Causes of restless leg syndrome
In most instances, the causes of restless leg syndrome is unknown. This is called primary or idiopathic restless leg syndrome, which has a gradual onset that often gets worse with age. Although there isn’t a known direct cause of it, it often seems to have a genetic basis and occurs in families. Some neurologists believe that an imbalance, or lack, of certain neurotransmitters can have an impact, in particular the chemical dopamine. Dopamine is involved in controlling muscle movements, so an imbalance or difference in how the body handles the chemical, may be responsible for involuntary leg movements.
Secondary restless leg syndrome comes on suddenly, as opposed to the gradual onset of primary restless leg syndrome. This is usually associated with another factor such as:
It is predicted that between 10-25% of pregnant women report symptoms of restless leg syndrome, with the condition typically occurring in the third trimester of the pregnancy and symptoms often disappearing by the time the baby has been delivered, or not long after.
For women who have never experienced restless leg syndrome before pregnancy, there are a number of theories as to why it might have occurred including iron deficiency, a rise in oestrogen, folate deficiency or changes to circulation.
- Iron Deficiency
Levels of iron is also thought to be associated with the development of restless leg syndrome with one study finding around 25% of restless leg patients had an iron deficiency, meaning that it is important to test for the levels of iron in cases of restless leg syndrome. Symptoms usually worsen at night, which is when levels of iron typically tend to dip. Symptoms also tend to develop in the last three months’ of a pregnancy, which is also a time when iron levels are low.
Some forms of medication can make restless leg syndrome worse. Anti-sickness drugs, as well as sedating antihistamines can block the dopamine receptors in the brain, causing RLS, and certain antidepressants which increase levels of serotonin in the brain can also make the condition worse.
- Kidney Disease
Symptoms of restless leg syndrome are common in patients with chronic kidney disease who are on dialysis, although the actual cause is unknown.
Treating restless leg syndrome
If a doctor is able diagnose the underlying condition that is causing the restless leg syndrome, they are better able to treat it. For example if the sufferer has an iron deficiency, an iron supplement may be prescribed. Similarly if symptoms are worsened after taking certain types of medication, your doctor may be able to prescribe alternatives.
For mild cases of restless leg syndrome and ones which aren’t linked to a health condition, a few simple lifestyle changes may help ease symptoms. These can include:
- Practicing good sleep habits such as going to bed and waking up at the same time every day and taking the time to wind down before bed.
- Avoiding caffeine and alcohol especially in the evening.
- Stopping smoking.
When experiencing symptoms, it may help to apply a hot or cold compress to your legs, take a warm bath or do some relaxation exercises such a yoga.
For more frequent or severe episodes of restless leg syndrome, your doctor may recommend dopamine agonists medication, which work to increase dopamine levels. These have side effects so it is important to take advice from your doctor about the most appropriate course of treatment.