Thirst—duh. And yes, dark pee means you need to drink up. But your breath, mood, and need for sweets may also be telling you you’re dehydrated.
You have stinky breath
Saliva works 24-7 to wash away food particles that collect on your tongue, between your teeth, and along your gums after you eat. If your mouth is dry, those itty bitty leftovers allow bacteria to grow, thrive, and give you bad breath. Sip water throughout the day to help keep your mouth moist. And if you need a little extra freshening: chewing gum (preferably sugarless) or sucking candy (also sugarless) helps stimulate saliva.
Actually, that’s probably the right word if you’re a guy. For women, skimping on fluids may put you in full-on you-know-what mode. Researchers at the University of Connecticut’s Human Performance Laboratory tested the mood and concentration of 25 women who drank healthy amounts of water one day, and then didn’t over the next two days. When slightly dehydrated, the women reported fatigue, irritability, headaches, and difficulty focusing. In a separate test, men who were mildly dehydrated also experienced fatigue and had a tough time with mental tasks. But when it came to mood changes, women’s soured much more than men’s, according to the study. Scientists are still trying to figure out why. (Good luck with that.)
You crave cookies
You might mistake needing to drink for wanting to nosh, especially after exercise. “After a strenuous session, we are not only dehydrated, but our glycogen stores are depleted,” says Kim Larson, RDN, sports dietitian and spokesperson for the Academy of Nutrition and Dietetics. Glycogen is a form of stored carbohydrates that our body uses as fuel; the cravings are just our bodies telling us we need more of it. “Not everyone wants sugar after exercising, but when you are tired, it’s tempting to reach for it!” says Larson. Better choices: Fruits and dairy foods deliver the quickest, most nutrient-rich carbohydrates to supply energy when glycogen stores are low; plus, many fruits and yogurt have a high water content to also help you rehydrate. Here are other
Your skin does this weird 'tent-ing' thing
Pinch the back of your hand and hold for a few seconds; when you let go, your skin should snap back into position pretty quickly. If it’s slow to return to normal, take that as a cue to hydrate. “Skin turgor—a measure of skin elasticity—begins to decrease with a fluid loss of about 5 percent, which is considered mild dehydration,” explains Chris G. Adigun, MD, a board-certified dermatologist in Chapel Hill, North Carolina. With more moderate or severe dehydration, the pinched-up skin will remain “tented” in place. You know why else you should stay hydrated? To help you look younger. “Especially as we age, the visible appearance of the skin of the face improves with superb hydration,” adds Adigun
You have a crappy workout
Dehydration reduces blood pressure and makes the heart work harder, which impacts how much you can push yourself, explains Larson. “Even a 2 to 3 percent fluid loss affects your ability to get a good workout,” she says; “and more than 5 percent dehydration decreases exercise capacity by about 30 percent.”
You drive like you’re drunk
You pee before you hit the road and barely sip your bottle of water en route, all in the name of avoiding pit stops. We get it. But according to research published in Physiology and Behavior, driving while dehydrated may be just as dangerous as getting behind the wheel intoxicated, in terms of how many mistakes you could make on the road. British researchers had study participants take two-hour drives (using a simulator): when they were well-hydrated, there were 47 driving errors; dehydrated, slips-up—including lane drifting and late braking—more than doubled to 101. Dehydration causes fatigue and affects our cognitive abilities, like clear thinking and reaction time, says Larson.
You feel woozy when you stand too fast
Blood volume and pressure drops when you’re dehydrated, which can leave you feeling dizzy or faint, or bring on that rush of light-headedness after you quickly get up from sitting or lying down.