I have olfactory halucinations (they aren't nearly as common as they were in years past), and when I told my dad that he told my doctor who said "OMG BRAIN TUMOR" (it is a legit sign of one) so I had to have a test to see if I had one or not, turns out I don't, thankgoodness. The test I had last semester didn't really tell me anything. I wasn't allowed to see the actual numbers and graphs. The gave me a sheet that said "there is something wrong with you, you likely have generalized anxiety disorder, but we don't know what else, so you should totally take this pill!" lol.