system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: What's happening physically when you have a stuffy nose and eat something like wasabi? where does all that snot go?
gpt
That stuffy feeling inside your nose isn't all snot.  a lot of it is simply the tissue inside your sinuses swelling up and blocking the airflow.  think about what happens inside a penis during an erection:  blood engorges the tissues inside a penis that makes it swell up and become stiff.  The same process happens inside sinuses when we are sick.  So what wasabi and horseradish does make your nostrils flare open more and it also makes the snot mucus inside your sinuses thin out and drip more easily.  some of the snot comes out the front, some of it goes down the back of the throat.  This is a good thing because the thinner mucus is less hospitable towards bacterial growth and it can contribute to you feeling better.  You'll get a similar feeling from Chinese mustard.