What causes olfactory hallucinations (phantosmia)?
Answer From Jonathan Graff-Radford, M.D.
An olfactory hallucination (phantosmia) makes you detect smells that aren't really there in your environment.
The odors you notice in phantosmia are different from person to person and may be foul or pleasant. You may notice the smells in one or both nostrils. The phantom smell may seem to always be there or it may come and go.
Phantosmia may be caused by a head injury or upper respiratory infection. It can also be caused by aging, trauma, temporal lobe seizures, inflamed sinuses, brain tumors, certain medications and Parkinson's disease. Phantosmia can also result from COVID-19 infection.
Talk to your health care provider if you have symptoms of phantosmia, so that they can rule out any serious underlying disorders that may be causing olfactory hallucination.
Parosmia is another smell disorder that's similar to phantosmia. But in parosmia a smell that's present in your environment is changed and doesn't smell as it typically would. Parosmia can occur with damage to the olfactory system. This can happen after a severe respiratory infection, including COVID-19.
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Jonathan Graff-Radford, M.D.
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June 21, 2022
- Flint PW, et al., eds. Olfactory function and dysfunction. In: Cummings Otolaryngology — Head & Neck Surgery. 7th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed May 23, 2022.
- Lafreniere D. Taste and olfactory disorders in adults: Anatomy and etiology. https://www.uptodate.com/contents/search. Accessed May 23, 2022.
- Lalwani AK. Olfactory dysfunction. In: Current Diagnosis & Treatment in Otolaryngology — Head & Neck Surgery. 4th ed. McGraw-Hill Education; 2020. https://www.accessmedicine.mhmedical.com. Accessed May 23, 2022.
- Whitcroft KL, et al. Olfactory dysfunction in COVID-19: Diagnosis and management. JAMA. 2020; doi:10.1001/jama.2020.8391.
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FAQs
Phantosmia may be caused by a head injury or upper respiratory infection. It also can be caused by aging, trauma, temporal lobe seizures, inflamed sinuses, brain tumors, certain medicines and Parkinson's disease. Phantosmia also can result from a COVID-19 infection.
What neurological disorder causes phantosmia? ›
Neurologists play an important role in treating many central causes of phantosmia, such as migraines, neurodegenerative disorders such as Alzheimer or Parkinson disease, and temporal lobe seizures.
Can anxiety cause olfactory hallucinations? ›
Anxiety can cause a wide variety of symptoms, including phantom smells (phantosmia or olfactory hallucinations). Many people with anxiety report smelling odd smells that other people do not smell.
What does it mean if you smell things that aren't there? ›
Smelling things that aren't there is called phantosmia. It can be unpleasant and affect how things taste. But it isn't usually serious and may go away by itself in a few weeks or months. See your GP if the strange smell doesn't go away in a few weeks.
What type of brain tumor causes phantom smells? ›
a brain tumour in the temporal lobe could lead to sensations of strange smells (as well as other symptoms, such as, difficulty with hearing, speaking and memory loss)
Why do I suddenly have phantosmia? ›
Phantosmia may be caused by a head injury or upper respiratory infection. It also can be caused by aging, trauma, temporal lobe seizures, inflamed sinuses, brain tumors, certain medicines and Parkinson's disease. Phantosmia also can result from a COVID-19 infection.
What diseases cause olfactory hallucinations? ›
Olfactory hallucinations have been observed in various neurological disorders, such as Alzheimer's disease (3), Parkinson's disease (4), epilepsy (5), and migraine (6), as well as in psychological disorders, such as schizophrenia (7), depression (8), bipolar disorder (9), and substance abuse (10).
Should I be worried about olfactory hallucinations? ›
In most cases, phantosmia isn't a cause for concern and will go away in time. However, in rare instances, it could indicate a more serious health condition, such as Parkinson's disease, stroke or a brain tumor.
How do you fix olfactory hallucinations? ›
If symptoms persist for more than a few days, doctors may first recommend simple treatments, such as using a saline solution to rinse out mucus from the nasal passages. Certain drugs may help people with long lasting phantosmia control their symptoms: anesthetic to numb the nerve cells. steroid creams or sprays.
What medications cause olfactory hallucinations? ›
Phantom odor perception may be a side effect of antidiabetic or antihyperlipidemic agents. Among people taking proton pump inhibitors, phantom odors may also be a consequence of gastric gas reflux.
You may experience changes in your sense of smell and taste. In particular, some people with hypothyroidism report phantosmia (where you experience phantom smells, like cigarette smoke)
How come I can smell some things but not others? ›
Parosmia is a distorted sense of smell. It happens when smell receptor cells in your nose don't detect odors or transmit them to your brain. Causes include bacterial or viral infections, head trauma, neurological conditions and COVID-19. Parosmia is usually temporary, but in some cases, it's permanent.
Why do I think I smell but no one else does? ›
Olfactory reference syndrome (ORS), also known as olfactory reference disorder, is an underrecognized and often severe condition that has similarities to obsessive-compulsive disorder (OCD) and body dysmorphic disorder (BDD). People with ORS think they smell bad, but in reality, they don't.
What were your first signs of a brain tumor? ›
Changes in speech (trouble finding words, talking incoherently, inability to express or understand language) Changes in the ability to hear, smell or see, including double or blurred vision. Loss of balance or coordination. Change in the ability to feel heat, cold, pressure, a light touch or sharp objects.
Can MS cause phantom smells? ›
A study that evaluated the ortho- and retronasal olfactory functions in MS patients found that 75% of the 16 investigated patients showed a quantitative olfactory disorder, 6.25% reported parosmia, and 18.75% reported phantosmia (29).
What are stress related phantom smells? ›
Common Phantom Smells Anxiety Symptom Descriptions
This unusual smell is not related to anything you've eaten or been exposed to. Common descriptions of the smell include, “tinny,” “metallic,” “ammonia-like,” “blood-like,” “sour,” “bitter,” “acidy,” “vinegary,” “rotting-like,” and repugnant, to name a few.
Is phantosmia a symptom of MS? ›
A study that evaluated the ortho- and retronasal olfactory functions in MS patients found that 75% of the 16 investigated patients showed a quantitative olfactory disorder, 6.25% reported parosmia, and 18.75% reported phantosmia (29).
Is phantosmia a mental disorder? ›
No, but phantosmia may be a symptom of some mood disorders and mental health conditions, including schizophrenia. Phantosmia refers to detecting smells that aren't really there. It's a symptom of many common conditions, including allergies, colds and upper respiratory infections.
Is phantosmia a symptom of Parkinson's disease? ›
Olfactory dysfunction is a prevalent non-motor symptom in Parkinson's disease (PD), affecting approximately 65–90% of subjects. PD patients may also report odor perception in the absence of any external source, often referred to as olfactory hallucinations (OHs) or phantosmia.
What is the difference between phantosmia and parosmia? ›
Unlike parosmia, in which your nose is still able to smell something, phantosmia is when your smell receptors “hallucinate” and detect odors that aren't there. The smells may range from good to unpleasant. Phantosmia isn't constant; it can come and go.
