[rsync]

Ok, but did you try exercising?

I mean this seriously:

your body naturally dilates your entire respiratory system in response to oxygen demand - and not by a trivial amount.

As someone who has a suspected less than perfect septum, and experiences allergies from time to time, I have gone from simply noticing the dilation effect to actively pursuing it as a remedy.

Which is to say, if I stay the night somewhere with indoor cats, I alleviate the symptoms by going for a run …

YMMV. IANAD. HNY!