Restless leg syndrome (RLS), or Willis-Ekbom disease, is a condition of the nervous system that causes an overwhelming urge to move the legs or other parts of the body, like the arms, chest or face.
This is usually accompanied by an unpleasant crawling sensation or even pain in the affected area.
It is a common condition, affecting up to 10% of the adult population in the US and Europe according to the BMJ. It can also develop at any age, but typically occurs in people over 65 years old.
Studies suggest that women are also twice as likely to be affected than men.
The intensity of the sensation can vary greatly between sufferers. Some people describe it as tingling or itching in the muscles, whereas others describe it as a painful cramp or an electric shock.
The frequency of symptoms also varies, with some experiencing symptoms daily and others having only occasional episodes.
Restless leg syndrome typically occurs or is worse in the evening, or at night when an individual is at rest. Moving or rubbing the area can provide relief, although this is only temporary.
Restless leg syndrome can be a debilitating condition, causing significant impairment to an individual’s daily life. This is in part due to the condition’s potential to prevent a sufferer from falling or staying asleep.
Restless leg syndrome and disturbed sleep
As symptoms of restless leg syndrome often occur or become worse at night, sufferers are typically forced to constantly move the affected area, or get out of bed to walk around.
Even if they do fall asleep, jerking movements known as periodic limb movements in sleep (PLMS) can be violent enough to wake themselves as well as their partners.
Poor sleep can in turn lead to insomnia and daytime fatigue, causing difficulties at work and in carrying out daily tasks.
Due to its ability to interrupt sleep, restless leg syndrome has also been categorised as a sleep disorder.
Despite how common it is, and the pain and difficulty it can cause, restless leg syndrome is often misunderstood.
Even today, sufferers are sometimes disregarded by friends and family and misdiagnosed by health professionals.
According to the Restless Leg Syndrome Foundation, there is also an association between restless leg syndrome and depressive disorders, with the risk of developing depression being 2 to 4 times higher in those with restless leg syndrome. The foundation notes that sleep disruption is a likely contributing factor.
While the exact cause of the condition is still unknown, restless leg syndrome has recently started to receive more recognition. Research into potential treatments is still ongoing, while advice on how to alleviate symptoms can be more easily obtained from a healthcare professional or found online.
Symptoms of restless leg syndrome
Restless leg syndrome is characterised by an irresistible urge to move, as a result of strange sensations in the legs, chest, face or arms. If it is in the legs, it usually affects the feet, thighs and calves.
Some individuals experience the symptoms of restless leg syndrome more frequently than others.
Sufferers of restless leg syndrome may describe the sensation in a number of ways:
- tingling, burning or throbbing in the muscles
- muscle ache
- an electric shock
- an itch that cannot be scratched
- crawling sensation on the skin
- pins and needles
- a fizzing sensation inside the blood vessels
- leg cramp (especially in the calf)
This sensation typically gets worse when you are not active, such as when you are in bed or relaxing.
As a result, you may be forced to move the affected area throughout the night, or repeatedly get up and walk around. This can lead to feeling excessively tired in the daytime, or even insomnia.
You may also experience uncontrollable jerking or twitching in your sleep which can wake you up. This is known as Periodic Limb Movements in Sleep (PLMS) and can also contribute to sleep disturbance.
The movements are abrupt and can occur repeatedly throughout the night (typically every 20 to 40 seconds). Although less common, you might also experience this when you are awake and relaxed.
Causes of restless leg syndrome
There are two types of restless leg syndrome: Primary RLS and Secondary RLS.
In Primary RLS, there is no known cause or underlying health condition. It is more common than Secondary RLS and there is evidence to suggest it runs in families.
Secondary RLS occurs alongside certain underlying health conditions, including:
- pregnancy (research has shown up to 26% of pregnant women can be affected by restless leg syndrome)
- iron deficiency anaemia
- Parkinson’s disease
- chronic kidney disease
The exact reason for this is currently unknown.
Alternatively, a study by the American Academy of Neurology suggests having a specific brain structure may also contribute to developing restless leg syndrome.
Therefore, while there have been studies into possible contributing factors of restless leg syndrome, there is not yet enough research to determine the exact cause.
How iron and dopamine might affect restless leg syndrome
The basal ganglia (a part of the brain involved in controlling movement) uses dopamine to communicate with the nervous system. In conditions where dopamine levels are low, this process may be affected.
You naturally produce less dopamine later in the day, which may explain why restless leg syndrome is often worse in the evening and at night.
This may also explain why restless leg syndrome can also occur in people with chronic conditions like diabetes. Research conducted by the Sleep Research Society suggests that nerve damage in such conditions may also lead to lower levels of dopamine.
Iron is also a possible factor in the development of restless leg syndrome as, according to Frontiers in Molecular Neuroscience, iron is involved in the metabolism of dopamine. Therefore, there is a possible link between low iron and issues with dopamine regulation.
Again however, there is not yet enough conclusive research to confirm that low dopamine levels are the cause of restless leg syndrome, nor to confirm the effects iron levels have on dopamine.
There is also an association between depressive disorders and restless leg syndrome. The reason for this is unclear, and counter-intuitively, antidepressants are actually a possible trigger of restless leg syndrome.
Preventing restless leg syndrome
There are a few suspected triggers of restless leg syndrome that you might encounter daily. You can avoid these triggers by making some changes to your lifestyle, including:
- exercising regularly
- maintaining a regular sleep schedule (e.g. avoid naps and have a set bedtime)
- avoiding caffeine
- avoiding alcohol
- avoiding smoking
Pregnancy is also a known trigger of restless leg syndrome. It is particularly common to experience symptoms during the third trimester, although these usually disappear four weeks after delivery.
If you suffered from restless leg syndrome beforehand, then you may find the symptoms get worse during pregnancy. These symptoms may not always improve after birth.
Medication which may trigger restless leg syndrome
Some medications which may trigger symptoms of restless leg syndrome, include:
- beta blockers
- calcium channel blockers
- anti-nausea drugs
If you suspect one of these medications may be triggering symptoms of restless leg syndrome, you should continue to take them, but make an appointment with a doctor to discuss the issue.
Treating symptoms of restless leg syndrome
There are a number of ways to manage sleep difficulties as well as the sensations caused by restless leg syndrome.
While you can get immediate relief from the milder symptoms using methods that you can try at home, a doctor may advise you use medication to treat more severe symptoms.
Immediate relief from symptoms of restless leg syndrome
You can get immediate, short term relief from milder episodes of restless leg syndrome using the following methods:
- massaging the affected area
- taking a hot bath
- applying a hot or cold compress
- distracting yourself by reading or watching television
- relaxation exercises (yoga, tai-chi, walking, stretching)
Some have also recommended the use of magnesium oil spray. This can be bought at local health shops or large pharmacies.
Medications to treat restless leg syndrome
If all else fails and symptoms of restless leg syndrome still persist after trying these methods, a doctor may advise taking certain medications. Speak to your pharmacist or doctor for further guidance before taking any medications.
For more regular symptoms, dopamine agonists or Levodopa may be recommended. These work by increasing the amount of dopamine available.
A doctor may advise taking anticonvulsant drugs which help calm hyperactivity in the brain to help relieve symptoms.
To manage the pain caused by restless leg syndrome, a doctor may advise taking strong painkillers.
They may recommend a low dose of sleeping pills can also if you experience insomnia or other sleep disturbances during severe episodes.
Speak to your pharmacist or doctor for further guidance on whether to use these medications and how to get and use them.
Secondary RLS can potentially be treated by addressing an underlying condition, like treating iron deficiency anaemia.
Restless leg syndrome can be a difficult condition to live with and has not always received the recognition it deserves.
In recent years however, increased awareness has improved access to information, and sufferers can now learn how to manage the condition online or with the help of a doctor.
Despite this, more research is still required before the causes of restless leg syndrome can be fully understood.