What is that smell?

It may not seem like an especially concerning or troublesome symptom. After all, what's the big deal about having superpower smelling abilities? You can smell the flowers, the gourmet food, and the freshly brewed coffee better than anyone else. But, for many patients hyperosmia is not a blessing and is more than a simple annoyance. It can cause extreme discomfort, even making patients sick at times.

Research studies examining impaired or heightened sense of smell have been focused primarily on patients suffering from neurological disorders, like Alzheimer’s and Parkinson’s disease. Only recently, have researchers begun to investigate the connection between olfactory disorders and autoimmune diseases. 

And, while there have been many anecdotal reports from Lyme disease patients complaining about their sensitivity to smells, there has never been a study examining the association between Lyme disease and hyperosmia — until now.


Study finds 50% of patients with Lyme disease reported having a heightened sense of smell, also called hyperosmia.

After administering questionnaires to 16 serologically positive Lyme disease patients and 18 control subjects, researchers found that 50% of the patients with Lyme disease suffered from hyperosmia, versus none of the control subjects. The findings were published in the Arquivos de Neuro-Psiquiatria Journal. 

“The high prevalence of this olfactory disorder found in our study suggests the need for further studies of olfactory function in this disease,” concludes the authors. “It would also be of interest to carry out longitudinal studies to evaluate the response of hyperosmia to antibiotic pharmacotherapy.”

In my own unofficial Facebook poll, 86% of the 22 responders reported experiencing difficulties with smell after their Lyme disease diagnosis.

In contrast, a decreased sense of smell, hyposmia, has been described in patients diagnosed with Fibromyalgia and COVID-`9. Fibromyalgia patients had “significantly lower thresholds of smell compared to healthy controls.” The investigators did not address hyperosmia.

Hyposmia was observed in 42 % patients with Fibromyalgia compared to 15 % of patients with systemic sclerosis and 4% of the healthy controls. “Our findings suggest that there is a decrease in the sense of smell both in Fibromyalgia and systemic sclerosis patients compared with healthy controls.”

Although having an altered ability to smell, whether lessened or heightened, may seem insignificant, these studies are a reminder of how vast the presentations can be in Lyme disease patients. And, how much more we still have to learn about this disease.

22 Replies to "What is that smell?"

  • Carole Houle
    06/08/2022 (4:11 pm)

    What is the reason i smell smoke ? Sometimes i get nauseous its there all the time. I have chronic lyme my DR. started me on clarythromycin and 3 days after i started to smell smoke i asked him if that drug could be a side effects of it and he said he did not think that it was. I stopped it and the smell is still very much there. At night i have to put lavender oil under my nose other wise i cant sleep. Is it cause by lyme, how long will it stay like that? Thank u.

    • Dr. Daniel Cameron
      06/10/2022 (3:22 pm)

      I have a few patients in my practice with a heightened sense of smell as their main issue. They often improve if I can treat their Lyme disease.

  • Jojo
    04/28/2022 (10:46 am)

    For any woman of experiencing perimenopause, please note that hyperosmia is DEFINITELY linked to perimenopause. It is fairly widely experienced, but seldom mentioned in the research/information regarding perimenopause. Olfactory processing a hormonal levels go hand in hand from what I have been able to discern. I am currently experiencing hyperosmia. I noticed it about for 2 years or so ago. Some report that the condition goes away within months or years. Hope this helps anyone looking for a cause.

  • Josephe Buchanan
    11/04/2021 (12:42 am)

    I was diagnosed with Lyne Disease at 16 years old. I took doxycycline and had to take the antibiotics again at the age of 39. At 41, I developed a terrible case of hyperosmia. After taking drug test the Lyme has not returned but these hyperosmia symptoms remain. I don’t know what to do. My lungs hurt. I think stress is partly due to it. I became sick in March of 2021 and has a fever for 2 weeks. After that sickness which may have or may not have been Covid 19, my sense of smell has heightened to the point of extreme annoyance, pain, and discomfort. I am look for answers. At 42, I don’t have the it in me to fight this forever. It is ruining my life. I am allergic to everything.

    • Justin
      12/04/2021 (6:24 pm)

      lungs hurting? sounds like Babesia

  • Tyler
    12/28/2020 (6:12 am)

    Two tests have come back negative, but on top of the fatigue, sleep-ruining joint issues, brain fog, and headaches, I’m CONSTANTLY wondering “what’s that smell?!” I stopped going to certain stores because their distinct smells were too overpowering (meanwhile, “how is no one else reacting to this?!”) and I’m INCESSANTLY sniffing around my house, trying to locate a couple of maddening smells. I used to Frebreeze the office before my overnight shift at a group home, and as a teacher, I would step out of my classroom to track down an odor (from the hall? a closet? the bathroom??) I’ve donated clothes that were washed in detergent I couldn’t stand–the smell just wouldn’t come out!–and now buy the one I CAN tolerate in bulk, in case it ever becomes unavailable.

    Maybe it’s an OCD thing. Maybe it’s fibromyalgia. But I swear it’s all undiagnosed Lyme disease.

    • Dr. Daniel Cameron
      12/28/2020 (7:29 am)

      I typically advise my patients to consider Lyme disease if they have combination of fatigue, sleep issues, brain fog and headaches along with changes in smell. I have written a couple blogs on this topic. https://danielcameronmd.com/central-sensitization-syndrome-worsens-lyme-disease/ I also work with my patients to rule out other illnesses. Call my office at 914 666 4665 if you have any questions.

    • Vera
      09/25/2021 (12:00 pm)

      Thank you very much for this text. We live in south east Europe. My mother is suffering from hyperosmia for years. Doctors of course have no clue what is it, behave like they never heard condition like this can occur. Solution they gave is to sit at home and not to go anywhere. For me is also interesting that she can tolerate natural strong smells like lavender, mint etc and even certain detergent for laundry , that we also buy in bulk for just in case they stop producing it. With certain strong perfumes, detergent, deodorants, home chemicals she react so strong that she feel like heart will jump out and she becomes red in her face and feel like dizzy and fainting. Same as some people who replied to this topic she became a home prisoner, not going anywhere not receiving anyone. After this text for sure I am going to test her on lyme. Also she had a full hysterectomy same as madam who wrote a comment below. It seems she is not that unique case not sure why doctors behave like they never heard about someone having that problem ever before. She doesn’t have autoimmune disease diagnosed, but there are some members in the family who are.

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