--- title: 12 Reasons Why Dehydration Is Bad for Your Body description: Dehydration can do more to your body than make you feel thirsty, spurring health effects from fatigue and bad breath to distracted driving canonical: https://time.com/3894844/water-dehydration/ author: TIME article:opinion: false article:content_tier: free article:published_time: 2015-05-26T13:19:02.000Z article:modified_time: 2026-02-22T07:35:02.517Z article:section: Health og:title: 12 Reasons Why Dehydration Is Bad for Your Body og:description: Being dehydrated can take a toll on your body and even your mind og:url: https://time.com/3894844/water-dehydration/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltcc2c73d86c6388ce/69885171524fc04086df2c76/3536-000236a-copy.jpg?branch=production&width=355&quality=75&auto=webp&crop=16:9 og:image:width: 355 og:image:height: 200 og:image:alt: empty-drinking-glass og:type: article twitter:card: summary_large_image twitter:title: 12 Reasons Why Dehydration Is Bad for Your Body twitter:description: Being dehydrated can take a toll on your body and even your mind twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltcc2c73d86c6388ce/69885171524fc04086df2c76/3536-000236a-copy.jpg?branch=production&width=355&quality=75&auto=webp&crop=16:9 ---  # 12 Reasons Why Dehydration Is Bad for Your Body > Sponsored content. 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Health Matters is TIME's daily health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free daily newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. by [Linda Melone / Health.com](https://time.com/author/health-com/) ## Linda Melone / Health.com Contributor May 26, 2015 1:19 PM UTC  Empty Drinking Glass Empty Drinking Glass Getty Images by [Linda Melone / Health.com](https://time.com/author/health-com/) ## Linda Melone / Health.com Contributor May 26, 2015 1:19 PM UTC It doesn’t take much to become dehydrated. Lose just 1.5% of the water in your body (the human body is usually about 60% H2O), and you’ve reached the tipping point of mild dehydration. It can be brought on [by many things](http://www.health.com/health/gallery/0,,20815262,00.html)—and it can do much more to your body than just make you feel thirsty. Dehydration also brings on health effects ranging from fatigue and smelly breath to more dangerous consequences like distracted driving. **It gives you bad breath** It’s easy to forget to drink water during a busy workday, but at the end of the day you may find people standing unusually far from you when you open [your mouth](http://www.health.com/health/gallery/0,,20354737,00.html). “Dehydration can give you bad breath,” says Marshall Young, DDS, a dentist in Newport Beach, Calif. “Saliva has important antibacterial properties. When dehydrated, the decreased saliva in the mouth allows bacteria to thrive, resulting in bad breath.” So drink up for your own sake, and for those around you as well. **It makes you crave sugar** Dehydration can mask itself as hunger, particularly [sugar cravings](http://www.health.com/health/gallery/0,,20847561,00.html). This may happen particularly if you’ve been exercising, says Amy Goodson, RD, sports dietitian for the Dallas Cowboys. “[When you exercise](http://www.health.com/health/gallery/0,,20909808,00.html) in a dehydrated state, you use glycogen (stored carbohydrate) at a faster rate, thus diminishing your stores more quickly.” So once you finish exercising, you will likely crave carbs to help you replenish those glycogen levels and get you ready for your next exercise bout. **It wrecks your workout** Even being slightly dehydrated affects your ability to put effort into your [workout](http://www.health.com/health/gallery/0,,20306717,00.html). “A 2% dehydration level in your body causes a 10% decrease in athletic performance,” says Goodson. “And the more dehydrated you become, the worse performance gets.” Measured by “perceived exertion,” how hard you feel you’re exercising, you might be working at a 6 but you feel like you are working at an 8, says Goodson. **It dries your skin out** Keeping [skin healthy](http://www.health.com/health/gallery/0,,20788790,00.html) and glowing requires drinking enough water, says Anne Marie Tremain, MD, a dermatologist with Laser Skin Care Center Dermatology Associates in Long Beach, Calif. “It’s best to hydrate from the inside out,” she says. “Depending on your lifestyle you may need to adjust your water intake.” If you work out every day or are a caffeine fiend, for instance, then you’ll need to drink more., because workouts make you sweat and caffeine is a diuretic, which can dehydrate you. For smooth, [moisturized skin](http://www.health.com/health/gallery/0,,20825198,00.html), Dr. Tremain also suggests keeping showers short (less than five minutes) and using only lukewarm water as hot water can dry your skin out even more. **It may affect your ability to drive safely** Few things are more uncomfortable than being stuck in traffic or on a long drive when you need to use the restroom. Logically, it makes sense to simply not drink water before hitting the road. But new research published in _Physiology and Behavior_ shows that the number of [driving errors doubled](http://www.sciencedirect.com/science/article/pii/S0031938415002358) during a two-hour drive when drivers were dehydrated versus hydrated—an effect similar to driving while drunk (defined by most states as .08% blood alcohol). Since often people purposely avoid drinking prior to a long road trip to prevent bathroom stops, dehydration could increase the risk of traffic accidents. **It makes you tired** A [mid-afternoon slump](http://www.health.com/health/gallery/0,,20784660,00.html) may have more to do with hydration than you think. “When you’re dehydrated your blood pressure drops, heart rate increases, blood flow to the brain slows – all of which can make you tired,” says Luga Podesta, MD, sports medicine specialist at Kerlan-Jobe Orthopaedic Clinic in Los Angeles, Calif. A lack of water to muscles also makes physical tasks feel more difficult and tiring. **It sours your mood** Cranky much? Drink a glass of water and your mood may change. “Neurological effects of dehydration can [cause irritability](http://jn.nutrition.org/content/early/2011/12/20/jn.111.142000.abstract),” says Dr. Podesta. A small study published in the _Journal of Nutrition_ tested [mood and concentration](http://jn.nutrition.org/content/early/2011/12/20/jn.111.142000.abstract) in 25 young women who were either given enough fluids to remain properly hydrated, or who became mildly dehydrated by taking diuretics and exercising. The dehydrated women—who were at a level that was just 1% lower than optimal—reported headaches, loss of focus, and [irritability](http://www.health.com/health/gallery/0,,20694928,00.html). **It can give you the chills** It may seem counterintuitive, but dehydration can bring on chills. “This occurs because your body starts to limit blood flow to the skin,” says Dr. Podesta. In addition, water holds heat, so if you become hydrated it can be more difficult to regulate your body temperature, which can make you become chilled faster, even when you’re not in a cold environment. **It can cause muscle cramps** A lack of water causes less blood circulation, which can make muscles cramp up, says Ray Casciari, MD, medical director of the La Amistad Family Health Center in Orange, Calif. “The body will protect its vital organs, so it shifts fluid away from muscles and anything that’s not vital,” he says. [Muscle cramps](http://www.health.com/health/gallery/0,,20706961,00.html) can be extremely painful, making muscles feel harder than normal to the touch. Changes in sodium and potassium through sweat loss can also contribute to cramping. **It makes you feel dizzy and foggy** Along with muscles, your brain also gets less blood circulation when you’re low on water, which can make you dizzy, says Dr. Casciari. Additionally, mild dehydration may affect your ability to take on [mental tasks](http://www.health.com/health/gallery/0,,20845146,00.html) and cause you to feel [foggy headed](http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8425835), according to a study from the _British Journal of Nutrition_. Interestingly, a study that appeared in the _Journal of Nutrition_ showed greater [mood changes](http://jn.nutrition.org/content/early/2011/12/20/jn.111.142000.abstract) in women than in men, both at rest and during exercise. **It can give you a headache** Dehydration can cause headaches in a couple of different ways. “Lack of water affects your body’s serotonin levels, which can give you headaches,” says Dr. Casciari. In addition, small blood vessels in the brain respond quickly to hydration levels (which is also behind hangover headaches), leading to dull aches and even full-blown migraines. Try downing a glass or two of water the next time you have a [headache](http://www.health.com/health/gallery/0,,20789184,00.html) and you may discover it disappears. You could also eat fruit, which contains a high percentage of water, Dr. Casciari suggests. **It constipates you** Your body needs water to keep things moving through your colon. When you’re not getting enough H2O, your body compensates by withdrawing more fluid from stool, making it harder and more difficult to pass. That said, it’s worth noting that drinking more water when you’re already properly hydrated won’t necessarily relieve [constipation](http://www.nature.com/ejcn/journal/v57/n2s/full/1601907a.html) caused by other factors, like the medications you’re taking, medical conditions, or a lack of fiber in your diet. [_This article originally appeared on Health.com._](http://www.health.com/health/gallery/0,,20924876,00.html) _Read next:_ [_12 Mental Tricks to Beat Cravings and Lose Weight_](http://time.com/3825798/beat-cravings-mental-tricks/?iid=time%5Freadnext) [_Listen to the most important stories of the day._](http://time.com/newsletter/the-brief/autoplay/?xid=spl-fullbrief-article) _More from Health.com:_ * [15 Big Benefits of Water](http://www.health.com/health/gallery/0,,20396298,00.html?xid=time) * [14 Surprising Causes of Dehydration](http://www.health.com/health/gallery/0,,20815262,00.html?xid=time) * [7 Easy Ways to Drink More Water](http://www.health.com/health/video/0,,20836567,00.html?xid=time) ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/3894844/water-dehydration/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3894844/water-dehydration/"},"headline":"12 Reasons Why Dehydration Is Bad for Your Body","datePublished":"2015-05-26T13:19:02.000Z","dateModified":"2026-02-22T07:35:02.517Z","description":"Being dehydrated can take a toll on your body and even your mind","url":"https://time.com/3894844/water-dehydration/","keywords":["Diet & Nutrition","Health Care","health insurance","Mental Health","Water","Healthcare","health"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/bltcc2c73d86c6388ce/69885171524fc04086df2c76/3536-000236a-copy.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Linda Melone / Health.com"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/bltcc2c73d86c6388ce/69885171524fc04086df2c76/3536-000236a-copy.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"empty-drinking-glass","caption":"empty-drinking-glass","creditText":"Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/dietnutrition/","name":"Diet & Nutrition"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/3894844/water-dehydration/","name":"12 Reasons Why Dehydration Is Bad for Your Body"}}]}] ```