I think I can help....
Some questions from a long-time sufferer of chronic sinusitis who has few or no symptoms, like you:
1) Does your head ever hurt when you bend over or when you sneeze?
2) Does anybody say you have a bad smell coming from your nose? (if no, do a test if you can)
3) Do you have a diminished sense of smell?
4) Where does your head hurt when you have a headache?
5) Do you have any known airborne allergies or
food sensitivities ?
6) Are your eyes ever puffy and swollen (even when you aren't having an allergic reaction, if you have allergies)?
7) When you sleep on your side, does that same side of your nose get stuffy?
8) Do you have post nasal drip?
Let's start with these... I can then tell you about my experiences... I have performed extensive research on the subject.... I would sure like to help somebody else who may have this condition...