system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When someone's lungs get filled with something other than air, why does hanging them upside down not work?

I mean either fluids like water, or heavier than air gasses like freon that displace air. I would think simply hanging upside down would drain whatever it is out and help fix the issue.
gpt
Because your lungs aren't simply empty bags. They are filled with many many, increasingly smaller branches that end in tiny avioli. And when you are dealing with passages this small, water tends to stay in their, much like getting water in your ear.