• image.alt
  • With Mayo Clinic neurologist

    Jerry W. Swanson, M.D.

    read biography
3 imperatives to transform health care in America. You're invited to watch it live

Free

E-newsletter

Subscribe to Housecall

Our weekly general interest
e-newsletter keeps you up to date on a wide variety of health topics.

Sign up now

Question

Phantosmia: What causes olfactory hallucinations?

What causes olfactory hallucinations (phantosmia)?

Answer

from Jerry W. Swanson, M.D.

Many people are sensitive to certain smells, but in an olfactory hallucination (phantosmia), you detect smells that aren't really present in your environment.

The odors detected in phantosmia vary from person to person and may be foul or pleasant. They can occur in one or both nostrils and usually can't be masked by food.

Phantosmia most often occurs as a result of a head injury or upper respiratory infection. It can also be caused by temporal lobe seizures, sinusitis, brain tumors, migraine, Parkinson's disease and stroke.

Because phantosmia can in rare cases be an indication of a serious underlying disorder, consult your doctor if you experience such symptoms.

Note that phantosmia is different from another disorder of sense of smell, known as parosmia, in which a smell is present in your environment but is distorted. Parosmia can occur with damage to the olfactory system, such as after a severe respiratory infection. In this situation, there's usually also a loss of sense of smell.

Next question
Neurontin side effects: How do I manage them?
References
  1. Mann NM, et al. Anatomy and etiology of smell and taste disorders. http://www.uptodate.com/ index. Accessed May 1, 2012.
  2. Flint PW, et al. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa.: Mosby Elsevier; 2010. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-323-05283-2..X0001-8--TOP&isbn=978-0-323-05283-2&uniqId=230100505-57. Accessed May 1, 2012.
  3. Smell and taste disorders. The Merck Manuals: Home Edition for Patients and Caregivers. http://www.merckmanuals.com/home/ear_nose_and_throat_disorders/nose_sinus_and_taste_disorders/smell_and_taste_disorders.html. Accessed May 1, 2012.
  4. O'Brien EK (expert opinion). Mayo Clinic, Rochester, Minn. May 29, 2012.
AN01684 June 23, 2012

© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

  • Reprints
  • Print
  • Share on:

  • Email

Advertisement


Text Size: smaller largerlarger