Many get thirsty just before bedtime, but why? New research has looked at mice and found that their brain makes them thirsty when it expects dehydration.

The mice also drink before sleep and the researchers noted that their thirst was not due to dehydration or high body temperature, which is otherwise the most common causes of thirst.

Instead, it must be the brain’s internal clock that felt that it just was time to sleep for a long period. Since the mice cannot drink during sleep, the thirst center in the brain anticipates thirst in advance.

The discovery the researchers made, was that the brain can make us thirsty even if we hydrated enough. They believe this apparent behavior among mice is the same in humans.

The team’s findings provide new insights into the brain’s circadian clock and the research is another step in understanding how the brain regulates fluid balance.


C. Gizowski et al. “Clock-driven vasopressin neurotransmissionmediates anticipatory thirst prior to sleep.” 2016. DOI: 10.1038/nature19756