Research discovers a surprising connection between two movement disorders
For many years, restless legs syndrome (RLS) was treated as a movement disorder that caused simple sleep problems. Recent research has pushed the idea of RLS and Parkinson’s disease into the spotlight. A large Korean study, published in JAMA Network Open in October 2025, followed almost 20,000 adults for up to 15 years and found that people with RLS were about 60% more likely to later receive a diagnosis of Parkinson’s disease (PD).
On the surface, that sounds alarming. A higher risk always catches attention, especially when the condition in question is a serious movement disorder like Parkinson’s. At the same time, the absolute numbers are still small, and the way RLS is treated may change what happens next. The message is less about fear and more about paying attention to what the data quietly tells us.
Lead researcher Dr. Myeonghwan Bang, of the National Health Insurance Service Ilsan Hospital in South Korea, said “It may be more reasonable to interpret RLS as a potential risk factor for Parkinson’s rather than an early symptom.”
What is restless legs syndrome (RLS)?
Restless legs syndrome is a neurological and sleep-related condition where a person feels an uncomfortable urge to move their legs, and sometimes their arms. The feeling is often described as tingling, crawling, pulling, or a mild electric shock under the skin. Symptoms usually start or get worse in the evening, and they can make it very hard to fall asleep or stay asleep.
RLS affects an estimated 5–10% of adults, with symptoms more common in women and in people over the age of 50. The condition can show up on its own, or together with other health issues such as iron deficiency, kidney disease, pregnancy, or certain medications. The pattern of symptoms, and how they respond to movement, helps doctors separate RLS from other problems such as leg cramps or nerve pain.
Scientists think RLS involves changes in brain pathways that use dopamine, a chemical messenger that helps control movement, motivation, and sleep cycles. Iron handling in the brain also seems to play a role. Because of this mix, some researchers now talk about RLS as a restless legs syndrome risk factor that shares some biology with Parkinson’s, even though the two conditions still look different in many key ways.
A study that followed 20,000 adults for 15 years
The Korean team drew on data from the national health insurance system between 2002 and 2019. They identified 9,919 adults with newly diagnosed RLS and matched each one with a similar adult without RLS, based on age, sex, income level, and other health conditions. This kind of long-term Korean health cohort study lets researchers see how often a later diagnosis such as Parkinson’s shows up in each group.
By the end of follow-up, about 60% more people in the RLS group had received a Parkinson’s diagnosis compared with the non-RLS group. In simple terms, out of 10,000 adults with RLS, roughly 160 were diagnosed with Parkinson’s, compared with about 100 out of 10,000 adults without RLS. That is a meaningful difference, but Parkinson’s disease still remained relatively rare overall.
The researchers also looked at treatment patterns. Among people with RLS, those who were treated with dopamine agonist medications had a Parkinson’s rate of only 0.5%, while those who did not receive these drugs had a rate of 2.1%. This suggests that early and active treatment could deliver real RLS treatment benefits, possibly including a lower chance of later Parkinson’s, although the study cannot prove that treatment alone is responsible.
Why dopamine matters
Dopamine sits at the center of both conditions. In Parkinson’s disease, brain cells that make dopamine slowly die in a key movement area called the substantia nigra. This loss leads to classic PD symptoms such as tremor, stiffness, and slowed movement. In RLS, dopamine signaling seems to be unstable, especially at night, which can disturb both movement and sleep and create a link between dopamine and sleep disorders.
Medicines called dopamine agonists act like dopamine at its receptors. They are used in both RLS and Parkinson’s care. Examples include chemicals such as pramipexole and ropinirole, which are often prescribed in low doses for restless legs and in higher or combined doses for PD. On IsraelPharm, products like Mirapex and Requip are well-known dopamine agonists sold worldwide in these settings.
Other dopamine medications are more focused on Parkinson’s. These include add-on treatments like Ongentys and Comtan, anticholinergic medicines such as Kemadrin, and combination tablets such as Stalevo and Sinemet. Patch-based options like Neupro and enzyme blockers such as Azilect round out the list.
In the Korean study, people with RLS who were treated with dopamine agonists had a later and lower rate of Parkinson’s diagnosis. One possible reading is that earlier support for the dopamine system may help protect some brain cells, contributing modestly to Parkinson’s prevention. Another option is that treatment simply smooths out early Parkinson’s signs, delaying when doctors label the condition. The data are promising, but they do not close the case.
Could RLS be an early sign of Parkinson’s?
Experts have debated for years whether RLS is a non-motor prodromal sign of Parkinson’s disease, especially when symptoms start after age 50, affect only one side, or are severe and frequent. In that picture, RLS would be an early warning that Parkinson’s is already developing in the background.
The newer research, including the Korean work, leans toward a different framing: RLS may stand on its own as a risk factor, not just an early phase of PD. In this view, both conditions share some pathways in dopamine and iron handling, but they are still distinct. That is why the phrase “RLS and Parkinson’s“ shows up so often in the medical literature. Researchers want to know how close the link really is, and whether treatment can change the story.
Expert commentary urges not making rushed judgement
Earlier work from groups such as the Richmond Veterans Administration Medical Center warned against drawing quick, firm conclusions. In real-world clinics, it can be hard to tell classic RLS apart from other types of leg discomfort seen in Parkinson’s, such as akathisia, leg motor restlessness, or simple stiffness from reduced movement. If these are mis-labeled as RLS, the link between the two conditions may look stronger than it really is.
Genetic studies add another layer. Large genome-wide association studies (GWAS) show that the strongest RLS risk genes, such as MEIS1 and BTBD9, do not line up with known Parkinson’s genes. This supports the idea that biology separates them, even if symptoms overlap. Researchers still treat RLS as a restless legs syndrome risk factor, but they do not see a single shared “Parkinson’s gene” hiding inside it.
Understanding the study numbers in context
Relative risk and absolute risk tell different stories. A 60% higher risk sounds big, but the absolute numbers from the Korean work stay fairly small. As noted earlier, out of 10,000 people with RLS, about 160 developed Parkinson’s over many years of follow-up. In 10,000 people without RLS, about 100 developed Parkinson’s.
From a public health point of view, that difference matters. It highlights RLS as a meaningful signal, not just background noise. At the same time, most people with RLS will never develop Parkinson’s disease. The main lesson is awareness, not panic: restless legs deserve attention, careful diagnosis, and thoughtful management, but they are not a guarantee of a future PD diagnosis.
What this study means for patients
For a person already living with RLS symptoms, the study highlights the value of proper assessment. A healthcare provider can check for iron deficiency, kidney problems, or medications that might worsen symptoms and can confirm that the pattern truly fits RLS rather than another condition. This careful work also helps separate RLS and Parkinson’s from other look-alike disorders.
Treatment may include lifestyle steps, iron replacement when needed, and medicines like dopamine agonists. Early, effective care can bring clear RLS treatment benefits, especially better sleep and improved daily function. Some researchers now wonder whether this early care, especially with dopamine agonists, might also reduce the long-term risk of Parkinson’s, although more research is needed before anyone can claim a definite protective effect.
Take away ideas: A reason for awareness, not worry
Putting the pieces together, RLS appears to be a modest but real risk marker for later Parkinson’s disease. It shares some biology with PD, especially in the dopamine and iron systems, but it is not simply an early stage of the same illness. The numbers tell a balanced story: higher risk than average, but still a low chance overall for any one person.
For families living with restless legs, the most useful response is practical: get a clear diagnosis, manage symptoms, and keep an eye on any new movement changes, especially tremor, stiffness, or slowed actions. Regular follow-up with a doctor who understands both conditions can help catch problems early without creating unnecessary fear.
IsraelPharm is a trusted pharmacy that takes care to provide clear information for people facing complex conditions, but nothing should take the place of direct contact with a trusted healthcare provider. At IsraelPharm, we can provide customers with reliable, affordable access to medications like pramipexole and ropinirole, used worldwide to manage both Parkinson’s and restless legs syndrome.
Frequently asked questions about RLS and Parkinson’s
Does having restless legs syndrome mean a person will definitely get Parkinson’s?
No. The Korean study and other research show that RLS is linked with a higher chance of later Parkinson’s disease, but most people with RLS never develop PD. One way to picture it is this: in 10,000 people with RLS, around 160 may be diagnosed with Parkinson’s over many years, compared with about 100 out of 10,000 people without RLS. The risk is higher, but Parkinson’s is still uncommon. RLS should be seen as a signal to take symptoms seriously, not as a guaranteed future outcome.
How strong is the restless legs syndrome risk factor for Parkinson’s?
In the large Korean health cohort, people with RLS were about 60% more likely to develop Parkinson’s than people without RLS. That level of extra risk is enough to get the attention of researchers and doctors, especially when combined with what is known about dopamine pathways in both conditions. At the same time, a 60% relative increase on a low baseline risk still leaves the absolute chance for any one person fairly small. This is why experts focus on awareness and follow-up rather than making bold predictions.
Can dopamine agonists for RLS lower the chance of Parkinson’s disease?
The study suggested that people with RLS who were treated with dopamine agonists had lower rates of later Parkinson’s than those who were not treated. This has led many to ask whether these medicines might help with Parkinson’s prevention. At this stage, the answer is “maybe, but not proven.” Treatment may truly protect brain cells, or it may simply delay or mask early Parkinson’s symptoms. Any decision to start a dopamine agonist needs to be made with a healthcare provider who can weigh benefits, risks, and alternatives.
What symptoms should make a person ask about both RLS and Parkinson’s?
RLS symptoms include an urge to move the legs, uncomfortable sensations that get worse during rest, and relief when moving, especially in the evening or at night. Parkinson’s disease, on the other hand, is better known for tremor, muscle stiffness, slow movement, and changes in balance or facial expression. When a person has both RLS and Parkinson’s, showing signs of restless legs and signs of tremor or slowed movement, it is especially important to ask a doctor to look at the full picture. Careful assessment helps separate overlapping conditions and guides the right treatment plan.
Do genes link RLS and Parkinson’s disease?
Both RLS and Parkinson’s can run in families, but genetic studies suggest that the two conditions do not share a simple, direct genetic pathway. For RLS, researchers have found several risk genes, including MEIS1 and BTBD9, which seem to affect brain development and dopamine pathways. Parkinson’s has its own set of genes. So far, large studies have not found strong overlap between the main genes for each condition. This supports the idea that RLS and Parkinson’s are related but still distinct, with some shared biology and some separate roots.
How can someone with RLS protect long-term brain health?
There is no guaranteed way to prevent Parkinson’s, even for people with restless legs syndrome. However, a person with RLS can take sensible steps that support overall brain and body health. These include getting a proper diagnosis, treating iron deficiency if it is present, reviewing medicines that might worsen symptoms, and considering appropriate RLS treatments, including dopamine agonists when recommended. Staying physically active, protecting sleep, and keeping regular check-ins with a healthcare provider can all help detect new problems early and keep quality of life as high as possible.
