What Are the Risk Factors?

When people first hear about Restless Legs Syndrome (RLS), they often wonder: Am I the only one with this strange problem? The answer is no. RLS is one of the most common neurological conditions worldwide, yet it remains underdiagnosed. In this article we look at how frequent RLS really is, who is most at risk, and what factors contribute to its development.

How Common Is RLS?

Large population studies in Europe and the United States show that 5 to 10 percent of adults experience RLS symptoms. That means that out of every 100 people, up to 10 may have the condition. In some groups, especially older adults, the number can be even higher.

Europe and USA: Around 5–10% prevalence.
Asia: Generally lower, often under 3%.
Germany (Dortmund study): Nearly 9% of adults reported symptoms, but only 1.6% required medical treatment.
France: A study in older adults over 60 years found a prevalence above 20%, showing how much age influences the condition.

These numbers make RLS one of the most frequent sleep-related neurological disorders, even more common than many people think.

Age and RLS

RLS can appear at almost any age—from childhood to old age—but the risk increases steadily with age.

Early-Onset RLS: Symptoms begin before the age of 35–45. This form often runs in families, progresses slowly, and may be mild at first.
Late-Onset RLS: Starts after age 45. This form is more often linked with other health problems (such as kidney disease, diabetes, or neuropathy) and may progress more quickly.

The fact that RLS can start so early shows that it is not just a condition of aging. Children and teenagers may suffer too, but they are often misdiagnosed as having “growing pains” or anxiety.

Gender Differences

Women are more likely to develop RLS than men. In most European studies, the prevalence is significantly higher among women. One explanation is the role of pregnancy and hormonal factors:

During pregnancy, especially in the third trimester, RLS symptoms are common. They usually disappear after childbirth but can return years later.
The risk of chronic RLS rises with the number of pregnancies a woman has had.

This female predominance suggests that iron metabolism and hormonal influences may play a key role.

Underdiagnosis: The Hidden Side of RLS

Even though RLS is common, many patients remain undiagnosed. Studies in the UK showed that fewer than 13% of patients with clear symptoms were given the diagnosis by their general practitioner. In some surveys, the number was as low as 7%.

Why?

Symptoms are sometimes dismissed as “nerves” or “circulation problems.”
Patients may struggle to describe their sensations clearly.
Many doctors are not fully trained to recognize RLS, despite the simple diagnostic criteria.

As a result, countless people suffer for years without knowing that effective treatment exists.

Risk Factors for RLS

While anyone can develop RLS, certain risk factors make it more likely.

1. Genetics

Family history is one of the strongest predictors. If a close relative—parent, sibling, or child—has RLS, your risk is 3–4 times higher. Genetic studies have identified several variations in specific genes, such as MEIS1, that increase susceptibility. These genes are involved in brain development and dopamine function.

2. Iron Deficiency

Iron plays a vital role in the brain’s dopamine system. Low iron levels, even without full anemia, can trigger or worsen RLS. This is why checking ferritin (a measure of iron stores) is a standard part of RLS evaluation.

Women, especially those with heavy menstrual bleeding, are at higher risk.
Patients with frequent blood loss, poor nutrition, or chronic illness may also be affected.

3. Pregnancy

As mentioned, pregnancy is a temporary but powerful trigger. Hormonal shifts and increased iron demand often combine to cause symptoms. While most women improve after delivery, some remain vulnerable.

4. Chronic Diseases

Several medical conditions are linked to secondary RLS:

Kidney failure (especially in patients on dialysis)
Diabetes
Parkinson’s disease
Peripheral neuropathy
Cardiovascular diseases

In these cases, RLS may be both a symptom and a complication of the underlying illness.

5. Medications

Certain drugs can provoke or worsen RLS symptoms, including:

Some antidepressants (SSRIs, SNRIs)
Antipsychotics
Antihistamines (especially older types used for allergies or sleep)
Dopamine-blocking drugs

Patients should never stop medication on their own but should discuss alternatives with their doctor.

6. Lifestyle and Environmental Factors

Sleep deprivation and shift work may intensify symptoms.
Caffeine, nicotine, and alcohol can make the condition worse in some individuals.
Long periods of immobility (air travel, long car rides) are typical triggers.

Early vs. Advanced Cases

Not everyone with RLS needs treatment. Some people experience only mild discomfort, perhaps once a week, and manage with simple lifestyle adjustments. Others have severe nightly symptoms that disrupt every aspect of life.

Doctors classify RLS as:

Intermittent RLS: Symptoms less than twice a week, often manageable without medication.
Chronic Persistent RLS: Symptoms at least twice a week for over a year, usually requiring treatment.

The Human Impact Behind the Numbers

Numbers and percentages are useful, but what matters most is how RLS affects daily living. Patients report:

Avoiding social activities like going to the cinema because sitting still is unbearable.
Dreading bedtime because they know they will struggle for hours.
Feeling exhausted and depressed after years of poor sleep.

This human cost explains why epidemiology matters: recognizing how common RLS is should push healthcare systems to improve awareness, diagnosis, and access to treatment.

Summary

Restless Legs Syndrome is far more common than most people realize, affecting up to one in ten adults in Europe and the United States. Women, older adults, and people with certain medical conditions are at especially high risk. Despite this, RLS often goes undiagnosed, leaving many people to suffer unnecessarily. Genetics, iron levels, pregnancy, chronic illness, and even certain medications can all play a role in triggering the syndrome.

Understanding the epidemiology and risk factors of RLS is not just academic knowledge—it empowers patients to seek help, discuss their risks with doctors, and recognize that they are not alone.