Restless legs syndrome (RLS) is a condition where people feel uncomfortable sensations in their legs, especially at night. Researchers discovered that RLS comes in two different types: one with pain and one without. This study of over 1,400 adults found that these two types are quite different. The painless type is linked to iron deficiency and general health issues like obesity and high blood pressure. The painful type is connected to other pain conditions like migraines and period pain. Both types are associated with anxiety and depression. Understanding these differences could help doctors diagnose and treat RLS better.

The Quick Take

  • What they studied: Whether restless legs syndrome with pain is different from restless legs syndrome without pain in terms of what causes it and what other health conditions come with it.
  • Who participated: 1,449 adult twins and family members (about 64% women) who answered detailed health questionnaires. Researchers also looked at 1,327 of these people’s history of iron deficiency.
  • Key finding: Painless RLS is mainly linked to iron deficiency and general health problems, while painful RLS is linked to other pain conditions like migraines and period cramps. Both types are connected to anxiety and depression.
  • What it means for you: If you have restless legs, knowing whether your symptoms include pain or not may help your doctor figure out what’s causing it and how to treat it better. However, this research is still early, and you should talk to your doctor about your specific symptoms.

The Research Details

Researchers used Twins Research Australia to send questionnaires to adult twins and their family members. Participants answered questions about whether they had restless legs syndrome, whether it was painful or painless, and about other health conditions they had experienced. The researchers then looked for patterns—did people with painful RLS tend to have certain conditions, and did people with painless RLS tend to have different conditions?

They used a statistical method called logistic regression to find connections between RLS types and other health conditions. They adjusted their results to account for differences in age and gender, since these factors can affect health conditions.

The study focused on comparing two distinct groups: people with painful RLS symptoms and people with painless RLS symptoms, to see if they had different patterns of other health problems.

This research approach is important because it helps doctors understand that RLS isn’t just one condition—it might actually be two different conditions that just happen to have similar symptoms. By finding what health problems go with each type, doctors can better figure out what’s actually causing someone’s restless legs and treat it more effectively.

This study used a large group of participants (over 1,400 people), which makes the findings more reliable. The study looked at real people’s actual health histories rather than just lab tests. However, the researchers noted that they didn’t have enough people with painful RLS in certain groups to test everything they wanted to. The study relied on people reporting their own symptoms and health conditions, which could sometimes be inaccurate. This is one study, so the findings need to be confirmed by other researchers before we can be completely certain.

What the Results Show

The study found clear differences between the two types of restless legs syndrome. Painless RLS was strongly connected to a history of iron deficiency—people with painless RLS were much more likely to have had iron deficiency than people without RLS. Painless RLS was also linked to several general health conditions including obesity, Parkinson’s disease, ADHD, high blood pressure, and vitamin D deficiency.

Painful RLS showed a completely different pattern. It was not connected to iron deficiency at all. Instead, painful RLS was strongly linked to other pain conditions: migraines, recurring stomach pain, growing pains in childhood, general chronic pain, chronic back pain, and period pain (dysmenorrhea).

Both types of RLS—painful and painless—were associated with anxiety and depression, suggesting that mental health may play a role in both forms of the condition.

The researchers had fewer people with painful RLS in their study, which meant they couldn’t fully analyze how painful RLS connects to other general medical conditions like they could for painless RLS.

An important secondary finding was that painless RLS showed no connection to pain conditions at all. This is significant because it shows that the two types of RLS are truly different—they don’t just differ in whether there’s pain, but they’re associated with completely different sets of health problems. The fact that both types were linked to anxiety and depression suggests that mood and mental health might be important factors in both forms of RLS, even though the physical causes appear different.

This research builds on earlier studies that suggested painful and painless RLS might be different conditions. Previous research hinted at this difference, but this study provides stronger evidence by looking at a large group of adults and their families. The findings support the idea that doctors should think of these as two separate conditions rather than just variations of the same problem. This aligns with growing scientific understanding that many conditions we thought were one disease are actually multiple related conditions.

The study had some important limitations. There weren’t enough people with painful RLS to fully analyze how it connects to general medical conditions, which means some conclusions are incomplete. The study relied on people’s memories and self-reports of their health conditions, which can sometimes be inaccurate. The study only included people from Australia who responded to questionnaires, so the results might not apply to all populations. The researchers couldn’t prove that these health conditions actually cause RLS—they only found that they occur together. Finally, this is one study, so the findings need to be repeated by other researchers to confirm they’re reliable.

The Bottom Line

If you have restless legs syndrome, pay attention to whether your symptoms include pain or not, and share this detail with your doctor. If you have painless RLS, ask your doctor to check your iron levels and vitamin D levels, and discuss whether you might have other conditions like high blood pressure or ADHD. If you have painful RLS, discuss with your doctor whether your other pain conditions (like migraines or period pain) might be connected. If you have either type of RLS, talk to your doctor about screening for anxiety and depression, as these are common with both types. These recommendations are based on this one study, so discuss them with your healthcare provider to see what makes sense for your situation.

This research is most relevant for people who have restless legs syndrome or think they might have it. It’s also important for doctors who diagnose and treat RLS. Family members of people with RLS should pay attention, since the study involved families and suggests RLS may run in families. People with iron deficiency, chronic pain conditions, anxiety, or depression should know that RLS might be connected to their conditions. However, if you don’t have restless legs syndrome, this research doesn’t directly apply to you, though it’s still interesting to understand how different health conditions connect.

If you start addressing potential causes (like iron deficiency or vitamin D deficiency), you might notice improvements in restless legs symptoms within a few weeks to a few months, though this varies by person. Mental health treatment for anxiety or depression might take several weeks to show benefits. It’s important to be patient and work with your doctor, as treating the underlying cause takes time. You should check in with your doctor regularly to see if treatments are working.

Want to Apply This Research?

  • Track your restless legs symptoms daily by noting: (1) whether symptoms occurred, (2) whether pain was present or absent, (3) time of day symptoms appeared, and (4) severity on a scale of 1-10. Also log any potential triggers like stress, iron-rich foods eaten, or sleep quality.
  • Start a simple log in your health app to record: iron-rich foods consumed daily, sleep quality and timing, anxiety or mood levels, and any other pain symptoms you experience. This data will help you and your doctor identify patterns and see if treating iron deficiency, vitamin D levels, or mental health improves your restless legs.
  • Set up weekly reviews in your app to look for patterns between your restless legs symptoms and other tracked factors. Share monthly summaries with your doctor to monitor whether treatments are working. Track changes in symptom frequency and intensity over 4-8 week periods to measure improvement. If you’re taking supplements or medications, note any changes in symptoms within 2-4 weeks.

This research provides important information about restless legs syndrome, but it is not a substitute for professional medical advice. The findings are from one study and should be confirmed by other research. If you think you have restless legs syndrome or are experiencing symptoms, please consult with a qualified healthcare provider for proper diagnosis and treatment. Do not start, stop, or change any medications or supplements based on this information without talking to your doctor first. This article is for educational purposes only and should not be used to self-diagnose or self-treat any medical condition.