During the day, gravity causes fluid to accumulate in the legs and ankles. When you lie down, this excess fluid is redistributed into the bl00dstream, forcing the kidneys to work harder and creating the need to urinate.

Additionally, changes in body temperature can disturb deep sleep, making you more sensitive to any internal signals, even when your bladder isn’t completely full.

Finally, stress and hormonal imbalances during the early morning trigger the nervous system, waking you up for no apparent reason.