Today I learned that if you’re coughing from post-nasal drip, blowing your nose helps.
I always thought of the front-of-nose and back-of-nose snot as being separate pools. I figured if I could breathe through my nose, and it wasn’t dripping from the front, I didn’t need to blow it. But no, it’s all the same pool. If it’s overflowing in the back, emptying it through the front stops that.