system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does a bladder last only as long as someone sleeps?

People generally sleep anywhere from 6 hours to 14 hours. No matter how long they sleep, they wake up and need to pee really badly. How come after sleeping 6 hours, it feels like  an accident is about to happen, yet people can sleep 14+ hours with no accident and results similar to 6 hours of sleep as far as needing to use the bathroom goes?
gpt
Your body actually produces a hormone called ADH, or "Anti-Diuretic Hormone," when you sleep. This hormone significantly reduces the amount of urine your kidneys produce. 
Some people who have issues with bedwetting, or getting up in the middle of the night to pee, actually have a problem producing this hormone.