Why does only one nostril stuff up?

We’ve all been there. Got a bad cold, drippy, stringy snot backing up the breathing passages, completely clogging one nostril. Yet the other one stays magically clear. Why? We’re symmetrical.

And why does the nostril that the Great Power chooses to be clogged change sides? What biological process tells the snot to flow to one side or another, but not both? Yes, I understand that a gene that would allow both nostrils to clog at once would tend to be selected out.

Sniffle. Anybody got a hanky?

i propose a system where both nostrils initially attempt to clog at the same rate. however, one nostril will have ever slightly more air flowing through it for various reasons (physiology, less irritants, freshly picked). the extra airflow will serve to clear or dry the forming mucus in that nostril. the drying of the mucus(booger formation) plugs mucus secreting pores, preventing further discharge. this results in a further shift of airflow to the clearing nostril. the other nostril will continue to clog to full capacity due to decreasing airflow.

It’s called the “nasal cycle” (although it’s got other names); the nose blocks off the olfactory organ from incoming air to allow one side to “rest up” and recovery its sensitivity to smells.

Maybe you have a sinus infection which is confined to one side? That’s happened to me before. If it doesn’t go away, or you get fever and/or a splitting headache that won’t go away, have your doc check it out.

If you are in bed the answer is gravity. If not then I’d say the answer is “you’ve never had a really bad cold”. :smack:

yeah, that happens to me all the time.

if it’s your left nostril, lie on your right side for awhile until it drains.
but, if you’re not careful, it drains down into the other one.

anyway, just be glad one of them works.

More formally, it’s called the ultradian rhythm. A Google search for this term (or for “nasal cycle”) would probably yield some useful information on it.

I can’t be helpful. I often stuff up entirely–both nostrils.

I wish only one of my nostrils were stuffed up!