system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why even when you’re dehydrated, do you sometimes have to wake up to urinate in the middle of the night?
gpt
Dehydration is your body not having enough water, that doesn’t mean that your body does not have any water. So you can still drink water, have you body ingest the water, and urinate even if you’re still dehydrated. 

Your body urinates all liquids you drink regardless of whether your dehydrated or not because dehydration is the result of an amount, or unable to reach that amount.