Hi, I'm wondering if anyone knows what this is. I can be going about my daily life and suddenly my sinuses will swell and I can't breathe through my nose, it feels like its all bunged up but not necessarily full of mucus (sorry its gross i know). I am allergic to all types of pollen, dog hair and dust (when its very dusty), but this sudden swelling can happen anywhere. does this sound like its probably allergies? it doesnt happen in really hot it happens more so in the winter and spring?