That's tiger purring, not some little kitty cat.

Those turbinates in the nostrils swell with blood to 'help' control airflow. If they are too big then they block the nasal passages. They can be cauterized to reduce their size - I should prolly have that done again.
Here's a tip - if you wake up with one side of your nose blocked then roll onto your side opposite the block. Within 10 minutes the swelling will go down in the turbinates and you will be able to breath normally through the side that was blocked.
WC