system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When you have one blocked nostril, how come it switches to the side you sleep on yet it doesn't drain out when you sit vertically/stand up or how come it doesn't come out when you try to blow it out?
gpt
There is erectile tissue in your nose that causes it to swell inside the nasal cavities. One nostril is always more open than the other and it switches every few hours. If you’re like me there’s no mucus just one side shuts down at night but when you get up and walk around it goes away. Basically you have a nose boner.