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.

With

Jonathan Graff-Radford, M.D.

From Mayo Clinic to your inbox

Sign up for free, and stay up to date on research advancements, health tips and current health topics, like COVID-19, plus expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

June 21, 2022 See more Expert Answers

See also

  1. EEG (electroencephalogram)
  2. Epilepsy and pregnancy
  3. MRI
  4. Seeing inside the heart with MRI
  5. SPECT scan
  6. Stereotactic radiosurgery
  7. Support groups
  8. Temporal lobe seizure
  9. Vagus nerve stimulation
  10. MRI
  11. Video: Vagus nerve stimulation