I have observed that drinking a full glass of water prior to sleeping leads to urination in the morning, as would be expected.
However, I have also observed that some people urinate more than once in the morning, often just an hour after the first full void.
I theorize that:
- The individual drank more than the bladder can hold, thus the body held onto the excess water until there was more room in the bladder before producing more urine.
- The body retains water overnight for some reason, and begins to move it to the bladder after one wakes up.
What is the physiology of urination that yields this pattern?