The Relationship Between Water And Sleep Health & How To Avoid Dehydration

If you didn’t see my earlier post about Sleep Doctor PM and want a better way to go to sleep and go back to sleep if you wake up, have a look.

The relationship between water and sleep is a two-way street

You have seen me write and speak about the importance of hydration to sleep from time to time. For example the New Year’s Eve, when on an airplane, or in making your supplements more effective, but these articles have all been about how certain situations can leave us dehydrated and its effects on sleep. Now there is new research looking at how sleep deprivation itself can make use more dehydrated.

But let’s start out with a more basic fact: While sleeping, just based on the humidity in our breath, we lose about 1 liter of water each night! So, we wake up dehydrated.

Sleep Doc Tip #1: When you wake up each day, drink 12-16 oz of water first thing in the am (room temp). This helps to replace your water loss immediately.

Sleep Doc Tip #2: Wait 90 min for your first cup of caffeine. Yes, I know you may have a habit of a caffeinated beverage being the first thing to enter your system, but remember caffeine is a diuretic! It makes you have to urinate, this is counter-productive with a dehydrated body. I recommend a second glass of water and then consider a coffee.

If sleep dehydrates us, then it seems as if we sleep less we should become less dehydrated, correct?


New research suggests that insufficient sleep can cause dehydration by potentially disrupting the release of a hormone that is key to hydration (Vasopressin). Newer research shows that sleepiness increases the risk of kidney disease, and we know that the kidneys play a significant role in hydration, and of course, drinking more water is good for kidney health.

New research from Penn State (published in the journal Sleep) shows us why this has become an important area to review. This research was a survey study looking at over 20,000 healthy young adults in the US and China. Subjects completed surveys about their sleep and gave urine samples. Medical News Today reports the research found that:

“people who regularly got 6 or fewer hours of sleep each night had more concentrated urine than those who got about 8 hours per night. ‘Short sleep duration was associated with higher odds of inadequate hydration in [American] and Chinese adults, relative to sleeping 8 hours,’”

And …

“More specifically, people who reported that they regularly slept for 6 hours or less each night were 16–59 percent more likely to be dehydrated than those who slept for 8 hours a night. These results applied to both population samples.”

The theory of why this is happening is based on the availability of an antidiuretic hormone Vasopressin which is an antidiuretic hormone that controls the body’s water balance during the day and night.

“Vasopressin is released both more quickly and later on in the sleep cycle,” Rosinger explained, adding, “If you’re waking up earlier, you might miss that window in which more of the hormone is released, causing a disruption in the body’s hydration.”

So, if sleep itself dehydrates a person and depriving myself of sleep makes one more dehydrated, what should you do?

Step 1: Determine your chronotype and calculate your bedtime, and stick to your schedule 7 days a week.
Step 2: Drink Caffeine between 90 min after you wake up and 2 pm, (remember, drink about 16oz of water first) stopping at 2 will eliminate the poor sleep quality effects caffeine may have long after ingestion.
Step 3: Limit alcohol to 3 hours before bed and have one glass of water for each alcoholic beverage (remember alcohol is a HUGE dehydrator).
Step 4: Exercise daily, and replace your sweat with WATER!
Step 5: When you are drinking your morning water, do it in front of the window to get your morning light exposure. This helps turn off the melatonin faucet in your head and remove brain fog.

Hydration and sleep are interrelated components of a healthy life, be sure to get enough of both this week and every week!