Always Thirsty at Bedtime? New Research Explains Why

For many of us, the last thing we do before turning in for the night is often grabbing a glass of milk or a warm cup of herbal tea. And if you’ve ever been responsible for getting kids to sleep, you’re most likely all too familiar with the repeated request for “one last” sip of water. Until now, we’ve all written our bedtime thirst off as just one more pre-bed habit or routine, but new research has suggested that it goes beyond that, and into an underlying biological need. One study published in a recent edition of Nature, an international journey of science, has found a link between our penchant for a bedtime drink and the functioning of our circadian clocks.

Usually, feeling thirsty is a response that is activated when our bodies feel that we could possibly at risk for dehydration, our body temperature skyrockets, or when our volume of plasma decreases. Bottom line – we generally feel thirsty when our bodily fluid levels are lower than the norm. But what the study discovered about nighttime thirstiness can’t be explained by any of the typical needs for the intake of fluids. Instead, it was found that in the hours before going to sleep, we become thirsty without any of the above reasons being present. So what gives?

The study’s team of scientists worked with lab rats to find the link between thirst and bedtime, and during their observations, they noticed that the rats that had no access to water just before going to sleep showed undeniable signs of dehydration when they woke up. This indicated that the rats were intuitively taking in more water before going to sleep, in order to ensure that they were adequately hydrated during the time that they were asleep, and unable to take in fluids, even though they (and almost every mammal, including us) continue to use bodily fluids due to food digestion and tissue repair.

In conclusion, the study found that not hydrating before bedtime could have some serious implications on our day-to-day lives, and that we owe it to ourselves to understand the mechanisms (and reasoning) of our natural drive for a drink before turning in for the night. This is especially true for third shift workers that are already going against their built-in body clock by being awake when everything inside of them is telling them that it’s time for bed. Sleeping when everyone else is awake can cause our bodies to not send the cues that we need to help keep us hydrated. And the same goes for those among us suffering from jet lag due to business travels. Thanks to the important findings of this research study, we may soon find that doctors and sleep professionals are recommending that we have a glass of water or cup of tea before turning in for the night, even if we aren’t feeling particularly thirsty, in order to make sure that we’re adequately hydrated for the long hours of sleep ahead of us, and to help ensure altogether better health, as well.