Introduction

Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a neurological condition that causes an overwhelming urge to move the legs. RLS is characterised by sensations often described as creeping, crawling, tingling, or throbbing. These sensations are typically worse during periods of inactivity, such as the evening and nighttime. It's estimated that 1 in 10 people are affected by RLS in some way.¹

RLS can significantly impact the sleep and quality of life of those affected. Therefore, it is essential to understand the causes and risk factors of RLS so that you can manage and treat it effectively. Addressing the potential underlying causes of RLS can lead to the disappearance of symptoms.²

Below, we look at the possible causes and risk factors that can lead to this syndrome.

Causes of restless legs syndrome

Most cases of restless legs syndrome have no exact underlying cause. However, the condition can be linked to the following factors:

Genetics

Research has found certain genes that can cause RLS. Indeed, it often runs in families and presents in people before the age of 40.² 

Dopamine

The natural drop in dopamine levels towards the end of the day can explain some of the symptoms of RLS - and make them worse in the evening and night. Dopamine is responsible for controlling muscle movements, so it may cause involuntary leg movements associated with restless legs syndrome.

Pregnancy

Some pregnant people experience the symptoms of restless legs syndrome for the first time when they are pregnant, and find that their symptoms disappear again after giving birth. Others find their RLS symptoms worsen during pregnancy.

Gender

RLS is more common in individuals assigned female at birth (AFAB) more than individuals assigned male at birth (AMAB). It is understood that hormonal changes can be a cause of restless legs syndrome, with the increase in oestrogen levels during pregnancy causing RLS symptoms due to oestrogen’s influence on dopamine synthesis. 

However, pregnancy hormones are not solely responsible for triggering RLS. If high levels of oestrogen were the only cause of RLS in pregnant people, then we would expect the rate or severity of RLS to decrease after menopause - but that doesn't happen. Additionally, the use of hormone replacement therapy does not lead to an increased incidence of RLS. In fact, RLS symptoms tend to become more severe during and after menopause.³

Age

Restless legs syndrome is more common in the elderly, with 10-35% or sufferers being above the age of 65.⁴

Risk factors for restless legs syndrome

Although restless legs syndrome is not associated with any serious medical conditions, some underlying conditions are known to make symptoms worse or can trigger the symptoms. These include:⁵ 

• Diabetes, which can cause nerve damage to hands and feet and worsen RLS symptoms
• Iron deficiency can affect the synthesis of dopamine in the body, which can cause RLS
• Kidney failure can cause iron deficiency, which in turn leads to more severe RLS symptoms
• Spinal cord conditions, such as slipped disc, spinal cord lesions and pinched nerves
• Parkinson’s disease - RLS can be a symptom of this disease, alongside weakness and decreased mobility in other limbs 
• Underactive thyroid - this can worsen RLS symptoms
• Rheumatoid arthritis — the pro-inflammatory cells present in rheumatoid arthritis patients have been shown to cause RLS symptoms⁶
• Fibromyalgia is closely related to RLS

Other triggers known to worsen RLS include:

• Medications such as antidepressants, antihistamines, and some antipsychotics.
• Excessive alcohol
• Excessive caffeine
• Smoking
• Being overweight
• Stress

Treatment of restless legs syndrome

RLS treatment aims to reduce the severity of patients’ symptoms and improve their quality of life. Whilst there is limited data available on RLS treatments, options include iron supplementation, medication to assist dopamine production, anti-anxiety drugs, and painkillers. Holistic therapies have not yet be tested thoroughly, but getting enough sleep and avoiding alcohol, caffeine and nicotine is thought to improve the symptoms of RLS.⁷

FAQs

What is restless legs syndrome (RLS)?

Restless Legs Syndrome (RLS), also known as Willis-Ekbom disease, is a neurological disorder characterised by an overwhelming urge to move the legs due to uncomfortable sensations such as creeping, crawling, tingling, or throbbing. These symptoms usually worsen during periods of inactivity, especially in the evening and nighttime.

How common is RLS?

RLS affects approximately 10% of the population in varying degrees of severity.

What causes RLS?

The exact cause of RLS is often unknown, but potential triggers/risk factors include:

• Genetics: certain genes linked to RLS can cause it to run in families
• Dopamine: low dopamine levels, especially towards the end of the day, can worsen symptoms
• Pregnancy: some people experience RLS during pregnancy, with symptoms often disappearing after childbirth
• Gender: individuals assigned female at birth are more likely to develop RLS, possibly due to hormonal changes
• Age: RLS is more common in the elderly

What are the risk factors for RLS?

Certain conditions and lifestyle factors can trigger or worsen RLS symptoms, including:

• Diabetes
• Iron deficiency
• Kidney failure
• Spinal cord conditions
• Parkinson’s disease
• Underactive thyroid
• Rheumatoid arthritis
• Fibromyalgia
• Medications (e.g., antidepressants, antihistamines, some antipsychotics)
• Excessive alcohol, caffeine, and smoking
• Being overweight
• Stress

How is RLS diagnosed?

Diagnosis is typically based on a patient’s symptoms and medical history. There is no specific test for RLS, but a doctor may conduct blood tests or other exams to rule out other conditions.

What treatments are available for RLS?

Treatment aims to relieve symptoms and improve quality of life. Options include:

• Medications, such as iron supplements, drugs to increase dopamine levels, anti-anxiety medications, and pain relievers
• Lifestyle changes: getting good sleep, regular exercise, and avoiding alcohol, caffeine, and nicotine

Can lifestyle changes help manage RLS symptoms?

Yes. Maintaining good sleep hygiene, engaging in regular physical activity, and avoiding triggers such as alcohol, caffeine, and nicotine can help manage RLS symptoms.

Is RLS a serious condition?

While RLS is not typically associated with severe medical conditions, it can significantly impact sleep and quality of life. Managing symptoms effectively is essential for overall well-being.

Can children get RLS?

Yes, children can develop RLS, especially if there is a family history of the condition. Symptoms in children may be mistaken for "growing pains". 

Is there a cure for RLS?

There is no cure for RLS, but symptoms can often be managed effectively with a combination of medication and lifestyle changes.

Summary 

Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a neurological disorder that causes individuals to constantly move their legs due to uncomfortable sensations like tingling, especially at night. RLS affects about 10% of people and can really disrupt sleep and quality of life.

The causes of RLS are mostly unknown, but an individual’s chance of developing the condition can be influenced by genetics, dopamine level drops, pregnancy, and age. Individuals assigned female at birth and elderly individuals are most at risk. Medical risk factors include diabetes, iron deficiency, kidney failure, spinal cord conditions, Parkinson’s disease, thyroid issues, rheumatoid arthritis, and fibromyalgia. Certain medications, excessive alcohol, caffeine, smoking, obesity, and stress can also make symptoms worse.

When treating RLS, the focus is on relieving symptoms and improving quality of life. This can involve iron supplements, dopamine-related drugs, anti-anxiety medications, pain relievers, and lifestyle changes such as practising good sleep hygiene and avoiding alcohol, caffeine, and nicotine.