For decades, Parkinson’s disease has been one of the most elusive neurological disorders to diagnose early. With no single test and symptoms that often don’t appear until the disease is well underway, patients and families are frequently left without answers for years. But a surprising breakthrough is changing that trajectory—and it started not in a lab, but in one woman’s nose.
Joy Milne, a retired nurse from Scotland, noticed a strange, musky smell on her husband years before he was diagnosed with Parkinson’s. What seemed at first like a personal quirk has now become a powerful tool in the push for earlier detection. Her ability to smell the disease—long before standard methods could identify it—has inspired scientists to develop a test that could one day change how Parkinson’s is diagnosed.
INCREDIBLE STORY — Meet the woman who can smell when someone has Parkinson’s….before they have symptoms.
— Steph McGovern (@StephLunch) September 20, 2022
Scientists working with Joy Milne have now developed a test to detect the disease using her knowledge.
It all started with a change in her husband’s smell: @PackedLunchC4 pic.twitter.com/zr0mNu3W00
A Unique Sense That Changed the Course of Parkinson’s Research
In the early 1980s, Joy Milne, a retired nurse from Scotland, noticed something strange about her husband, Les. His natural body odor had changed. It wasn’t something most people would notice, but Joy had an unusually acute sense of smell. She described it as a musky, damp scent—one that clung to his skin and clothes in a way that didn’t seem normal. Les, a doctor working in operating rooms, brushed it off as exposure to chemicals and hospital air. At the time, he was just 31 years old and showed no obvious signs of illness. But this persistent scent was the first sign of a disease that wouldn’t be diagnosed until 12 years later: Parkinson’s.
The couple had no idea that Joy’s sensory perception was alerting her to something science hadn’t yet caught up to. It wasn’t until after Les’s official diagnosis that things began to click into place. When Joy attended a Parkinson’s support group with him, she was struck by a realization—other people there had the same distinctive scent. This wasn’t coincidence. It was a biological marker her nose could detect, even when doctors couldn’t. That observation turned out to be far more than anecdotal. It became the basis for a groundbreaking research partnership that would push forward the science of early Parkinson’s detection.
Working alongside a team at the University of Manchester, Joy helped researchers identify how Parkinson’s disease alters the chemical makeup of sebum, an oily substance secreted by the skin. Using T-shirts and skin swabs from people with and without Parkinson’s, scientists were able to analyze the sebum and find thousands of unique chemical compounds. Of these, 500 were found to be different in individuals with the disease. These weren’t vague differences—they were consistent and measurable, pointing to a reliable biological signature. That data was key to developing a prototype test, in the form of a skin swab, that could potentially detect Parkinson’s years before visible symptoms emerge.
So far, lab results are promising. The swab test, which screens for specific chemical changes in sebum, has shown a 95% accuracy rate under controlled conditions. Researchers are now working to adapt the test for use in clinical settings like hospitals and general practices. If successful, this could radically change how Parkinson’s is diagnosed. Currently, diagnosis relies on observing physical symptoms and conducting neurological exams—processes that often take years and typically occur after substantial brain damage has already taken place.
Why Parkinson’s Affects Body Odor — The Science Behind the Smell
The idea that a neurodegenerative disease like Parkinson’s could alter the way someone smells might sound strange at first, but the science behind it is solid. Our bodies constantly release chemical compounds through skin, sweat, and breath. These compounds—known as volatile organic compounds (VOCs)—are byproducts of our metabolism. When something in the body changes, like hormone levels or neurological function, the chemical composition of these emissions can shift as well. In the case of Parkinson’s, those shifts are now believed to be detectable years before the disease becomes visible through physical symptoms.
Researchers studying Parkinson’s have found that the disease affects the skin’s production of sebum, a waxy, oily substance secreted by the sebaceous glands. Sebum naturally helps protect the skin, but in people with Parkinson’s, its chemical structure changes. These changes appear to be linked to oxidative stress and altered skin microbiome—both of which are known factors in Parkinson’s pathology. The altered sebum contains different levels and types of VOCs, which can produce a specific scent. For someone like Joy Milne, whose sense of smell is unusually acute, these changes can be detected by nose alone. For researchers, however, it requires sensitive instruments and detailed chemical analysis.
To investigate this further, scientists used a technique called mass spectrometry to identify and quantify the VOCs found in sebum samples. This analysis confirmed what Joy had sensed: a distinct molecular signature in the skin oil of people with Parkinson’s. Among thousands of compounds, around 500 showed consistent differences when comparing people with the disease to those without. These included changes in lipid-like molecules, which are commonly involved in cell membrane structures and metabolic processes—both of which are disrupted in Parkinson’s.
Importantly, this discovery doesn’t just provide a potential route to diagnosis—it also offers insight into the disease itself. Understanding why Parkinson’s changes skin chemistry could help researchers uncover new aspects of how the disease develops and spreads in the body. It also opens the door to studying other conditions that might leave similar chemical fingerprints. Already, researchers are exploring whether other neurodegenerative disorders, like Alzheimer’s, also alter VOCs in the body in detectable ways.
The story of Joy Milne and her unique ability to smell Parkinson’s disease pic.twitter.com/Ry933ksfA0
— Interesting As Fuck (@interesting_aIl) August 14, 2024
Why Early Detection of Parkinson’s Has Been So Difficult
Parkinson’s disease is notoriously difficult to diagnose in its early stages. There is no single test—no blood marker, no imaging scan—that can definitively confirm the condition. Instead, diagnosis typically happens after physical symptoms become obvious: tremors, slowed movement, muscle stiffness, and changes in posture or facial expression. By that point, research shows that 60–80% of the dopamine-producing neurons in the brain’s substantia nigra—a region critical for movement—are already damaged or dead. This means that by the time someone is officially diagnosed, the disease is already well advanced.
Right now, diagnosing Parkinson’s involves a combination of reviewing a patient’s symptoms, medical history, family history, and neurological exams. In some cases, a doctor might use brain imaging (like a DaTscan) to support the diagnosis, but these are often reserved for ambiguous cases and can’t provide definitive answers. This subjective, symptom-based approach also leaves room for misdiagnosis, especially in early stages when symptoms are mild or overlap with other conditions like essential tremor or depression.
This diagnostic lag has serious consequences. Without early identification, patients miss out on the opportunity to begin therapy or make lifestyle adjustments that might help preserve function for longer. While current medications like levodopa can improve symptoms, they don’t stop or slow the underlying neurodegeneration. If Parkinson’s could be detected earlier—before symptoms become irreversible—there would be a better window for clinical trials, earlier interventions, and potentially disease-modifying treatments once they become available.
That’s why Joy Milne’s story is so compelling to scientists. Her ability to detect Parkinson’s through smell—years before traditional diagnosis—offers a glimpse of what might be possible with the right tools. The skin swab test being developed at the University of Manchester, inspired directly by her experience, aims to fill this diagnostic gap. By identifying unique chemical changes in sebum, the test could allow clinicians to flag the disease much earlier than current methods allow.
What You Can Do—Practical Steps for Early Awareness and Support
While most people don’t have Joy Milne’s rare ability to detect illness through smell, there are still clear, practical actions anyone can take to stay alert to the early signs of Parkinson’s and advocate for timely care. Because current diagnostics rely heavily on observing symptoms over time, being proactive—and persistent—can make a difference in how quickly someone gets evaluated and supported.
First, it’s important to recognize that Parkinson’s often starts subtly. Early signs may include a slight tremor in one hand, changes in handwriting, reduced arm swing while walking, or softer speech. Other common but less obvious indicators include loss of smell, trouble sleeping (particularly acting out dreams), constipation, or unexplained mood changes like anxiety or depression. On their own, these symptoms might not raise red flags. But when they appear together or persist without a clear cause, it’s worth discussing with a healthcare provider.
If you or someone you care about is experiencing these symptoms, don’t wait for them to become severe. Bring them up clearly with a general practitioner and ask for a referral to a neurologist if there’s concern. Keep records—videos of movement changes, symptom logs, or notes on behavioral shifts can be useful in appointments, especially when symptoms are mild or inconsistent.
Advocacy matters, too. If you feel like your concerns are being dismissed or not taken seriously, don’t hesitate to seek a second opinion. Parkinson’s is often misdiagnosed in its early stages, and catching it earlier—even if treatments are limited—can help with planning, support, and access to services. It also opens the door to clinical trials, where people in early stages may be eligible for research into future treatments or diagnostics.
For those already diagnosed, there’s growing interest in non-traditional tools like smell testing. While the skin swab developed by Joy Milne and the University of Manchester team isn’t publicly available yet, it’s a development to keep an eye on. In the meantime, researchers continue to explore other non-invasive biomarkers—including changes in speech, gait, and even digital tracking through wearable tech.
