[maxerickson]

An ear nose and throat doctor (otolaryngologist) should be able to inspect the opening quite well by sticking a scope in your nose (I recently had this done). One of the reasons I visited the doctor was a persistent feeling of fullness in one of my nostrils.

With a Face and Jaw CT they would be able to walk you through it all visually (ask how much it will cost up front though, it varies a lot).

[mitm2mitm]

I did, they said I have a slightly deviated septum, but that's common for most people and there's no need for surgery. And that I shouldn't even feel anything.

I also checked my lungs and everything was fine.

It might be related to a mental disorder or something. I have anxiety and maybe other stuff that I never bothered to fix.