4 Sneaky Reasons You're Dehydrated That Have Nothing to Do with Drinking Water

Nutrition experts share four surprising reasons you're not staying hydrated aside from not consuming enough water.

Water is essential for life. Nearly 60% of the human body is made up of water. Not only is water fundamental in building cells, but it's also critical for regulating body temperature, healthy digestion and electrolyte balance. When your body does not receive the fluid it needs, it can become dehydrated, which can manifest itself in various forms. Mild symptoms of dehydration usually include dry skin, dry mouth, dark or infrequent urination, feeling tired and dizziness. However, serious complications of more extreme dehydration can include confusion, fainting and rapid breathing alongside an elevated heartbeat and shock.

Preventing dehydration is very important to help ensure your body is feeling and functioning at its best. While drinking water is an important part of the equation to avoid becoming dehydrated, it's not the only piece of the puzzle. Here are four surprising reasons that you may be dehydrated, with tips on how to prevent it from happening again.

Not sure if you're dehydrated? Read more: 5 Ways to Tell If You're Dehydrated

4 Sneaky Reasons You're Dehydrated That Have Nothing to Do with Drinking Water

1. Your Sleep Schedule

Whether you log 6 or 10 hours of sleep per day, both oversleeping and undersleeping can cause dehydration. A 2019 observational study published in the journal Sleep found that of the adults from China and America they studied, those who slept 6 hours or less per night were at greater risk of inadequate hydration than those who slept 8 hours. Relying on prior research from a study published in 2013 in Nature Neuroscience, Los Angeles-based registered dietitian and bestselling author of The MIND Diet, Maggie Moon, M.S., RD, suggests the reason that not sleeping enough may cause dehydration may be related to the disruption in the natural circadian signal—called vasopressin—that tells the body to hold on to fluids late in the normal sleep cycle.

While no consistent association was found when adults slept 9 hours or longer per night, Moon cautions on logging too many hours. Moon shares, "We lose fluids through our skin and respiratory systems all the time, even when at rest. Oversleeping simply means more hours of losing fluids without replenishment, leaving the body dehydrated."

2. Flying in a Plane

Traveling may disrupt many areas of your health, hydration included, notes performance dietitian Jenna Braddock, M.S.H., RD, CSSD, CPT. According to a 2020 research study published in Nutrients, the cabins of airplanes are controlled environments with much lower humidity than typical air. This can impact your fluid and hydration levels, leaving you dehydrated after your flight. While you may not be able to avoid flying, Braddock recommends traveling smart and trying to hydrate before your flight while continuing to do so during your trip.

3. Excessive Sugar Intake

The 2020-2025 Dietary Guidelines for Americans recommends limiting your intake of added sugar, as excessive sugar intake can affect multiple areas of health, surprisingly including hydration. Moon notes, "A [high-added-sugar] soda habit can lead to dehydration. It may sound counterintuitive since soda comes in a liquid form, but excessive [added] sugar intake can cause cells to flush their water into the body to help restore balance. This, in turn, can lead to frequent urination. All of this leaves the body dehydrated."

Science to support this is still evolving, with human studies needed, but there is available animal research supporting Moon's statement. A 2016 study published in the American Journal of Physiology Regulatory, Integrative and Comparative Physiology found that rehydrating with a soft-drink-like beverage actually worsened dehydration in animals while exacerbating dehydration associated with kidney damage. While animal studies are not ideal in extrapolating findings to humans, it does provide insight on the science on soda, added sugar and their potential effect on hydration in humans.

4. Drinking Alcohol

Maybe this is news to you, and maybe not. Either way, it's important to understand that drinking alcohol can lead to dehydration, "especially if you do not consume it with food and other beverages," Braddock shares. According to a 2018 study published in the journal Psychopharmacology, alcohol can suppress the hormone vasopressin, which acts to hold on to water in the body.

When this happens, this can affect urination, notes Braddock: "This action increases the amount of pee you produce and, therefore, you have to go more. If you're drinking and intoxicated, you might not be dialed into the fact that you're peeing a lot and need to drink water. A great strategy to employ when planning to drink alcohol is to be well hydrated first and then alternate drinks with a glass of water."

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Tips to Prevent Dehydration

Staying on top of hydration can help ensure your body keeps running as it should. While different strategies will work for different individuals, keep these tips from Braddock and Moon in mind to figure out what works best for you.

  • Keep a reusable water bottle filled on your nightstand. Start drinking it first thing in the morning as you get up to start your regular routine. And carry it with you throughout the day if you can.
  • Eat your way to hydration. Whole fruits and veggies with high water content offer good hydration in addition to other nutrients. For example, add more cucumbers, bell peppers, lettuce, tomatoes, citrus, berries and melons into your regular routine.
  • Use small, 8-ounce drinking vessels or mugs. Smaller cups are less intimidating, and many people welcome the use of a mug over a giant water bottle.
  • Make a new rule that attaches a small amount of water consumption to another activity you do frequently. This may look like taking a sip of water every time you sit back down at your desk, check your phone, walk into the kitchen, etc. Find what works for you and make it a routine.
  • Make your water more fun by switching up the flavors. Adding in natural, no-added-sugar flavorings like fresh citrus fruits, herbs, berries, and even pineapple cores and mango pits, is a great way to stretch your produce dollar even more while hydrating you at the same time!

The Bottom Line

Proper hydration is crucial for maintaining optimum health. While drinking adequate water can help prevent dehydration, it's important to be aware that other factors can contribute to dehydration as well, such as your quality of sleep, dietary patterns, travel and alcohol consumption. Focus on implementing easy-to-follow strategies to increase your fluid consumption to help prevent dehydration.

Up Next: Is Coffee Dehydrating? Here's What Dietitians Have to Say

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