How Do I Know If I’m Dehydrated?

by Kristine Lockwood      July 2, 2012


“Dry mouth, headache, and dizziness may occur.” Sounds like the fine print warnings on a medication bottle, right? But these symptoms can also indicate dehydration. Yikes! Dehydration occurs when the body loses too much fluid and can’t adequately replace it. This can happen for a number of reasons, but it’s most commonly due to fever (more water evaporates when body temperature goes up), diarrhea, vomiting, or long periods of exercise with excessive sweating (especially in hot or humid climates). When fluid levels get low (no, not like Lil’ John), the body goes on high alert. Read on to find out what signs to look out for, and how to avoid the dry-time blues in the first place.


Body of Water — The Need to Know
The body is approximately two thirds water, and losing some of it throughout the day in sweat, tears, and urine is totally normal. That lost water can be easily replaced by sipping on some good ol’ H2O or other drinks (sorry — not the alcoholic kind!) and many foods.


But when the amount of water drops too low for normal body functions (like maintaining temperature, protecting organs, and getting rid of all the bad stuff in the body through urination, perspiration, and… other things), it can lead to dehydration.


Especially as summer approaches, it’s essential to be on the lookout for the common signs of dehydration (or what’s medically referred to as “volume depletion”):
Dry mouth. The mouth may be first on the scene by becoming dry or sticky. Saliva is 99 percent water, after all.


Lowered blood pressure, headaches, and dizziness. Blood may be thicker than water, but it’s actually about 83 percent water, and less water circulating around the body means less blood, too. This can lead to lowered blood pressure, headaches, dizziness, and even a rapid heartbeat as the heart needs to pump faster to make up for having less blood.
Muscle fatigue. Lean muscle tissue contains about 75 percent water, so when the body’s short on water, muscles are more easily fatigued.
Dry, cool skin. When the body’s dehydrated, it does what it can to hold onto to whatever fluid is left — even stealing water from Peter to pay Paul. The skin is the first place to be robbed of water, resulting in dry, cool skin.

Thirst. Duhh…

Feeling lethargic and irritable.
Lack of urine. When the body’s short on fluid, no wonder it doesn’t want to expel even more! If the yellow tide (too much?) stops for more than 12 hours (or there’s only a very small amount of dark yellow urine), something’s definitely wrong.


Eat, Drink, and Stay Hydrated — Your Action Plan
The surefire way to beat dehydration? Start hydrating before that thirsty feeling hits. Drink plenty of fluids every day, and even though everyone is a little different when it comes to water requirements, 1.5 liters per day is a good rule of thumb[1].


Mild and moderate dehydration can usually be cured by drinking fluids to replace lost salts and fluids [2][3][4][5]. And while getting enough fluids during the day is important, not all beverages are created equal. Water is always a good go-to drink. Juice, milk, and coconut water are other great options[6]. And after intense workouts or activities, sports drinks are a good choice too, not only to replace water loss, but also to replenish electrolytes and sodium, which are just as essential to replace[7][8][9]. Don’t be afraid to eat salty foods after a hard hot-weather workout, either — serious athletes can suffer just as much from low salt levels as from low water levels! Two things to definitely steer clear of are alcoholic and caffeinated beverages (such as coffee, teas, and sodas), which tend to pull water from the body and may actually fuel dehydration.


As far as avoiding dehydration, the proof is in the pee. Clear, pale, or straw-colored, urine is good. If it’s darker, keep on drinking.
It’s important to drink more during hot weather, but even humid weather, high altitudes, feeling ill, and even cold weather necessitate some seriously hydrating action. And don’t forget to hydrate during exercise and activities! For every hour of strenuous activity or exercise drink one additional liter of fluid.

Expert’s Take
We asked two of our experts to weigh in on the topic. Here’s what they had to say:
Dr. John Mandrola:

“If I had a dollar for every case of heat-related heart problem that I have seen over the past two decades… well, I’d have plenty of money for a new Retina MacBook. As our summers grow hotter, heat-related illnesses are becoming more commonplace. People, even young healthy people, need to take the summer heat seriously. Here are a few tips.
Start the day topped off: One morning a few years ago, I had to drink 30 oz of water for a kidney ultrasound. It was hard to drink that much water, but I learned something that has stuck with me. I felt so good that day. My workout went better and I had better energy through out the day. Most of us don’t get enough!
On the dangers of caffeine: Though it is true that caffeine may help exercise performance in some cases, I have little doubt that caffeine impedes exercise in the heat. Not only is it a diuretic, which promotes fluid loss, but also, caffeine’s stimulant properties increase body temperature — a real negative in the heat.
Pre-workout hydration: Not enough summer exercisers start the workout topped off. Before I leave for a bike ride in the summer, I usually chug an entire bottle of water. Again, it’s hard to drink that much fluid, but when going out in the heat for a few hours, your body will thank you. One negative side effect: An early pee stop.”

Dan Trink:

“As critical as hydration is for regular, day-to-day activities, it is even more important when exercising to optimize athletic performance and body composition. As little as a two percent loss in hydration will affect performance in the weight room, so you want to make sure that you hydrate before and during your session.
A good general recommendation for both weight training and endurance athletes (assuming they are fully hydrated before training or the competitive event) is to drink 7 to 10 oz. of fluid every 10 to 20 minutes. If you are someone who perspires more than average or if you are competing in extreme climates or altitudes those amounts should increase.
Finally, keep in mind that hydration effects muscle growth, recovery and weight loss in a big way. As mentioned above, approximately 75 percent of muscle tissue is water. So it’s not hard to see how critical proper hydration is to gaining lean muscle mass. Water is used for countless metabolic processes, many of which effect recovery. From muscle repair, to protein synthesis, to nutrient absorption (digestion), water and hydration levels play a huge role. To put it simply, you cannot recovery properly without adequate hydration. Lastly, staying hydrated is a key component to a smart weight loss plan as it flushes toxins out of your system, keeps your digestive tract healthy and can even help you feel fuller, cutting down the risk of binge eating or consuming excess calories.”

This article was approved by Greatist Experts Dr. John Mandrola and Dan Trink. 


Works Cited
Water as an essential nutrient: the physiological basis of hydration Jéquier, E., Constant, F. Department of Physiology, University of Lausanne, Pully, Switzerland. European Journal of Clinical Nutrition, 2010 Feb;64(2):115-23. [↩]
Mild dehydration affects mood in healthy young women. Armstrong, L.E., Ganio, M.S., Casa, D.J., et al. Human Performance Laboratory, University of Connecticut, Storrs, CT. Journal of Nutrition, 2012 Feb;142(2):382-8. [↩]
Mild dehydration impairs cognitive performance and mood of men Ganio, M.S., Armstrong, L.E., Casa, D.J. et al. Texas Health Presbyterian Hospital, Institute for Exercise and Environmental Medicine, Dallas, TX. British Journal of Nutrition, 2011 Nov;106(10):1535-43. [↩]
Water, Hydration and Health Popkin, B.M., D’Anci, .KE., Rosenberg, I.H. Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina. Nutrition Reviews, 2010 Aug;68(8):439-58. [↩]
Water ingestion improves subjective alertness, but has no effect on cognitive performance in dehydrated healthy young volunteers. Neave, N., Scholey, A.B., Emmett, J.R., et al. Human Cognitive Neuroscience Unit, Division of Psychology, University of Northumbria, Newcastle, UK. Appetite. 2001 Dec;37(3):255-6. [↩]
Milk as an effective post-exercise rehydration drink. Shirreffs, S.M., Watson, P., Maughan, R.J. School of Sport and Exercise Sciences, Loughborough University, Loughborough, UK. British Journal of Nutrition, 2007 Jul;98(1):173-80. Epub 2007 Apr 26. [↩]
Rehydration and recovery of fluid balance after exercise Shirreffs, S.M., Maughan, R.J. Biomedical Sciences, University Medical School, Foresterhill, Aberdeen, Scotland. Exercise and Sports Science Review, 2000 Jan;28(1):27-32. [↩]
Rehydration after exercise in the heat: a comparison of 4 commonly used drinks Shirreffs. S.M., Aragon-Vargas, L.F., Keil, M., et al. Sport and Exercise Sciences Faculty, Loughborough University, UK. International Journal of Sports Nutrition and Exercise Metabolism, 2007 Jun;17(3):244-58. [↩]
Fluid and electrolyte balance in ultra-endurance sport. Rehrer, N.J. School of Physical Education and Department of Human Nutrition, Otago University, Dunedin, New Zealand. Sports Medicine,  2001;31(10):701-15. [↩]

source: greatist.com