system
Given the following post, respond as if you're commenting on Reddit:
human
What are you actually feeling when you feel like you have to pee?
gpt
You are feeling the stretch of the bladder. As the bladder fills, it becomes distended. As the stretch increases, nerves in the lining of the bladder send the urge to urinate to the brain. More distention increases the frequency of the signal, resulting in a stronger sensation.