Olfactory hallucinations

I have been having olfactory hallucinations for about 3 years now.  They last a few minutes, occur 1-2 times a month, and the smell is not unpleasant, a sort of chemical smoky smell.  It is very characteristic and now I recognize it right away as an hallucination.  (In the beginning I thought my neighbor was smoking something funny).  I don't have migranes (migraines), but I have had 2 or 3 visual migranes (migraines) in which there was a blurry line that stretched diagonally across my field of vision.  I wonder if these olfactory hallucinations could be related to the visual migranes (migraines) or if they may be related to a bike accident I had 6 years ago in which I had a concussion in which I was unconscious for ~15 minutes.
Thanks for your response!

[Dr. Kokil Mathur]

Hi
Welcome to the MedHelp forum!
Olfactory hallucination or phantosmia or phantom smell is usually due to seizure, or due to schizophrenia or depression or due to an aura of migraine. So yes, like visual migraine it can also be an aura of migraine. It can also be due to a problem in olfactory receptor mechanism. This could be due to a smell getting trapped by nasal polyps or tumors. Sinusitis with post nasal drip can cause both a phantom smell and nausea and this should be investigated first by an ENT.  Since it can be something serious, you should be seen by a psychiatrist, ENT specialist and a neurologist. It is difficult to comment beyond this at this stage. Hope this helps. Take care!

[cyclistc2c]

Thank you!