The Lamest Superpower: What It's Like to Smell Parkinson's Disease
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Published by Robbins Nest Alliance | Brain Injury Education for Caregivers and Families
For years, I told my husband he needed a shower.
He smelled like old milk — slightly sour, a little musty, the way laundry smells when you forget it in the washing machine too long. I asked if he'd spilled something. I checked his clothes. I noticed that the spot on the couch where he sat had the same smell.
I knew he was showering. The smell wasn't going away.
It took years — and a diagnosis — before I understood what I was actually smelling. And it took even longer to realize that what felt like the lamest superpower imaginable was actually something real, something documented, and something that other caregivers have quietly noticed and kept to themselves because it seemed too strange to say out loud.
This is that article. You are not imagining it.
Joy Milne Did It First — and Changed Everything
Joy Milne is a retired nurse from Perth, Scotland. Ten years into her marriage, she noticed her husband Les had developed an unpleasant, musty odor — particularly around his shoulders and the back of his neck.
She told him he wasn't showering properly. He became angry. The smell didn't go away.
Les was eventually diagnosed with Parkinson's disease. Years later, Joy and Les joined a Parkinson's support group. The moment they walked into the room, Joy noticed something that stopped her cold: the other people in the room had the same smell as her husband.
She mentioned it to researchers. They were skeptical — until they tested her.
Scientists gave Joy twelve t-shirts to smell — six from people with Parkinson's and six from people without it. She correctly identified the disease in all six cases. The one healthy person she categorized as having Parkinson's was diagnosed with the disease less than a year later, according to Scientific American.
Joy Milne had not imagined anything. She had detected something real.
The Science Behind the Smell
Following Joy Milne's discovery, researchers at the University of Manchester led by chemist Professor Perdita Barran used mass spectrometry to analyze sebum — the oily substance produced by skin glands — from people with and without Parkinson's disease.
Their findings, published in ACS Central Science, identified four key chemical compounds present in abnormal levels in the sebum of people with Parkinson's: eicosane, octadecanal, hippuric acid, and perillic aldehyde. The odor is concentrated in areas of high sebum production — primarily the upper back, forehead, and back of the neck.
A follow-up study funded by Parkinson's UK sampled 79 people with Parkinson's and 71 healthy individuals and identified over 500 compounds that differed between the two groups. The resulting skin swab test — which collects sebum from the upper back — can detect Parkinson's disease with 95% accuracy under laboratory conditions, according to Smithsonian Magazine.
The sebum overproduction that causes the odor is linked to dysfunction of the autonomic nervous system — the system that regulates involuntary body functions including skin oil production. Parkinson's disease disrupts autonomic function, and that disruption has a detectable chemical signature.
In other words: what caregivers have been noticing for years has a biological mechanism. It is not imagined. It is not a hygiene problem. It is the disease expressing itself through the skin.
What the Smell Is Actually Like
Joy Milne has described the Parkinson's odor as "musky" and slightly unpleasant — concentrated around the shoulders and back of the neck.
From a caregiver's perspective — someone who has lived with it for years — it is more specific than that. It is the smell of slightly sour milk. Old laundry left too long in the washing machine. Something faintly off that you can't quite locate.
It is subtle enough that most people would never notice it in a brief encounter. But for someone living in close proximity — sharing a home, a couch, a car — it becomes recognizable. And once you know what you're recognizing, you start to notice it elsewhere.
In waiting rooms. In shopping centers. In people you've just met who are moving a certain way, carrying themselves a certain way — and who smell, ever so faintly, like laundry gone wrong.
Why It Gets Stronger on Harder Days
One pattern caregivers often notice — and the research supports — is that the odor intensifies during periods of stress, fatigue, and symptom worsening.
This pattern has a plausible biological explanation. The autonomic nervous system dysfunction that drives sebum overproduction in Parkinson's may be further activated during periods of stress and physical depletion — potentially intensifying the odor during harder days. While this specific relationship has not yet been formally studied in peer-reviewed literature, the underlying mechanism is consistent with what researchers know about autonomic dysregulation in Parkinson's disease. What caregivers are observing intuitively may reflect a real biological pattern — even if science hasn't formally measured it yet.
In other words: when your loved one is having a harder day, their body is working harder, their autonomic system is more dysregulated, and the smell becomes more pronounced. What caregivers have been observing intuitively reflects a real biological process.
You were not imagining that either.
Why Caregivers Keep This to Themselves
Most caregivers who notice the smell say nothing — to doctors, to friends, sometimes even to each other.
It seems too strange. Too hard to explain. Too easy to dismiss. And there is the matter of dignity — telling someone they smell like sour milk is not a comfortable conversation, and watching them become self-conscious about something they cannot control is its own kind of grief.
So caregivers carry it quietly. They ask if the clothes are clean. They wonder if something spilled. They check the couch. And they never quite put it together until something — a support group, an article, a moment in a waiting room — makes the connection for them.
Joy Milne noticed the smell twelve years before her husband was diagnosed. Twelve years of knowing something was different before the medical system had a name for it.
That is not an unusual caregiver experience. It is a well-documented one.
What This Means for Early Diagnosis
The significance of Joy Milne's discovery extends far beyond the personal. Parkinson's disease is currently diagnosed based on physical symptoms — tremor, rigidity, slowness of movement — that typically appear after significant neurological damage has already occurred. By the time a diagnosis is made, the disease has often been progressing for years.
A skin swab test that can detect Parkinson's with 95% accuracy — before motor symptoms appear — would be one of the most significant advances in neurological diagnosis in decades. Researchers at the University of Manchester are collaborating with Harvard University to determine whether sebum-based biomarkers are detectable in people who have early warning signs of Parkinson's but have not yet received a diagnosis, according to Scientific American.
Joy Milne's nose — and the noses of caregivers like her around the world — may ultimately change when and how Parkinson's disease is caught.
If You Think You've Noticed This
If you are a caregiver for someone with Parkinson's disease or suspected Parkinsonism and you have noticed a smell you couldn't explain — you are not imagining it, you are not being unkind, and you are not alone.
What you are doing is what caregivers have always done: observing the person they love more closely than anyone else in that person's life. Noticing the things that don't quite fit. Carrying information that the medical system hasn't caught up to yet.
Tell your doctor. It may feel strange. Tell them anyway. Mention that you've noticed a change in body odor — particularly around the upper back and neck — that doesn't correspond to hygiene. Use the word sebum if it helps. Reference Joy Milne if you need credibility.
Your observations are clinically relevant data. They deserve to be taken seriously.
Related Reading from Robbins Nest Alliance
- Cognitive Decline After Brain Injury: Memory, Thinking, and Behavioral Changes
- 6 Early Signs of Brain Injury Families Often Notice First
- What Good Neurological Care Actually Looks Like
- 12 Questions to Ask After a Brain Injury Diagnosis
Citations
- Trivedi, D.K., et al. (2019). Discovery of Volatile Biomarkers of Parkinson's Disease from Sebum. ACS Central Science.
- Parkinson's UK. (2022). Smelling Parkinson's research could make it quicker and easier to diagnose Parkinson's. Parkinson's UK.
- American Parkinson Disease Association. The Smell of Parkinson's Disease. APDA.
- Scientific American. (2024). A Supersmeller Can Detect the Scent of Parkinson's, Leading to an Experimental Test for the Illness. Scientific American.
- Smithsonian Magazine. (2023). Woman Who Can Smell Parkinson's Helps Develop a Skin Swab Diagnostic Test. Smithsonian Magazine.
Robbins Nest Alliance is a 501(c)(3) nonprofit providing peer-reviewed brain injury education for caregivers and families. We are not a medical provider. This content is for educational purposes only. Always consult a qualified medical professional for diagnosis and treatment.