Hydration is one of those things you know you should be on top of, but you may not fully understand why.
“Hydration is important because our bodies really function [best with] adequate water balance,” says Shilpi Agarwal, MD, a board-certified family medicine physician in Washington, DC, and the author of The 10-Day Total Body Transformation. “Most organ functions require water in the right proportion to work — meaning your muscles, heart, and kidneys all need water and also need the body to be adequately hydrated in order to work properly.”
And what about?dehydration, to some a scary word that may be associated with health issues big and small? “Mild dehydration can lead to dizziness, fatigue, flushed skin, headache, impaired physical performance, and confusion,” explains Malina Malkani, RDN, who lives in Rye, New York, and is the creator of Solve Picky Eating, a program for parents of finicky eaters. If unaddressed, more extreme dehydration can even cause problems like labored breathing, increased body temperature, poor blood circulation, and seizures, Malkani adds. And according to the?Harvard T.H. Chan School of Public Health, dehydration can contribute to urinary tract infections and kidney stones.
To clear up confusion around hydration and dehydration, here are 10 things you must know to keep your health in tip-top shape.
1. Myth: If You’re Thirsty, You’re Already Dehydrated
There is some truth to this widely repeated statement. “This can be a really helpful reminder to people, because many of us aren't very in tune with our thirst, so once we realize we're thirsty, our body really is calling out for water,” says Ginger Hultin, RDN, the Seattle-based owner of Champagne Nutrition and the author of Anti-Inflammatory Diet Meal Prep.
But it’s not a one-size-fits-all indicator. “Each person needs to assess if this is actually true for them, because there are a lot of reasons a person can be thirsty. It's not 100 percent always because of dehydration,” says Hultin.
For example, something as simple as spicy food may make you thirstier than normal, according to the Cleveland Clinic. A sharp increase in thirst may also be a sign of a health problem like diabetes. It could be a side effect of a medication you’re taking; certain drugs cause dry mouth without causing dehydration per se. Regardless, it’s worth talking to your doctor if you’re much thirstier than normal to determine the underlying reason.
2. Fact: Dark Yellow Urine May Signal That You’re Dehydrated
If you’re concerned you’re not drinking enough water, try this quick trick: Check your urine color. “Urine color can be a pretty good indication of hydration status,” says Hultin.
An eight-level urine color chart lays out urine color from clear to dark yellow or brown — as posted by the U.S. Army Public Health Command. Though everyone is different, explains Hultin, the lightest four colors indicate that you’re hydrated, and the darkest four may mean that you’re dehydrated. If your pee falls in the brown range, you should seek medical attention, as Hultin advises this could mean severe dehydration.
3. Myth: To Avoid Dehydration, Drink as Much Water as You Can
When it comes to water, some people overdo it.
“There's a condition called hyponatremia, and it happens when the concentration of sodium in your body —?which is an electrolyte — gets too low,” says Hultin. “This actually causes the cells in your body to swell, and it is a life-threatening condition.”
While anyone can develop hyponatremia (so-called water toxicity), certain groups are at an elevated risk. That includes individuals with kidney failure, congestive heart failure, liver dysfunction, chronic severe vomiting or diarrhea, Addison’s disease, and people on some medications, such as antidepressants and diuretics, according to the Cleveland Clinic and Mayo Clinic. Research has shown?that endurance athletes may also be at risk for hyponatremia.?Previous scientific evidence points to certain illegal drugs, like ecstasy or MDMA, which may put users at risk for hyponatremia.
If you don’t have one of these risk factors or conditions, don’t fret. “For most healthy individuals, overhydration isn’t a serious concern, because the kidneys are able to excrete any excess fluid to maintain water and electrolyte balance, Malkani says.
When severe, symptoms of hyponatremia, MedlinePlus notes, can include convulsions, confusion, fatigue, headache, nausea, and muscle weakness. Seek medical attention immediately if you have these symptoms, especially if they’re severe.
4. Fact: Some Groups Are at Higher Risk of Dehydration Than Others
Meanwhile, some people need to prioritize hydration.
“[Dehydration is] very dangerous for children, pregnant women, and some older adults,” says Hultin. “Especially if someone in these categories is sick with a fever, vomiting, or diarrhea, they may need medical attention quickly to assess their hydration status.”
According to the Mayo Clinic, severe vomiting and diarrhea is often the main cause of dehydration in children. Meanwhile, older adults can actually have a lower volume of water in the body, and certain medications and conditions can make matters worse, the Mayo Clinic also notes. And severe morning sickness in pregnant women, known as hyperemesis gravidarum, can cause vomiting and lead to dehydration, per the National Health Service.
5. Myth: You Can Get Hydrated Only by?Drinking Liquids
Time to fill your grocery cart with produce — turns out, beverages aren’t the only provisions that will rehydrate you.
“While about 80 percent of our fluid intake comes from liquids, roughly 20 percent comes from the liquid found in watery foods like juicy fruits and vegetables,” explains Malkani. For example, the Mayo Clinic notes that some produce — like watermelon and spinach — is nearly 100 percent water by weight. Other hydrating foods include cucumbers, celery, radishes, watercress, grapefruit, cantaloupe, and strawberries, Malkani adds.
“On the flip side, salty foods and foods high in sodium are dehydrating because when the salt is absorbed and starts circulating in the blood, the body responds by drawing water out of the body’s cells to balance things out, causing increased thirst,” Malkani adds.
6. Fact: Too Little Sleep May Dehydrate You
Yet another reason to snooze enough: Adequate z's may help you stay hydrated. A?study published in February 2019 in the journal Sleep found that people who slept six hours each night were more dehydrated than those who regularly slept eight. A potential reason? Scientists point to the disruption of vasopressin, a hormone released at night that helps your body maintain its hydration status. If you feel off after a short night of sleep, rehydrate in the morning.
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7. Myth: Everyone Needs 8 Glasses of Water a Day to Avoid Dehydration
Like most things in health, hydration goals vary. “There will be a range of what people need — it's based on many factors, including physical activity, your diet and the environment that you live in, among others,” says Hultin. Other factors to consider are underlying health conditions, gender, age, and whether you are pregnant or breastfeeding.
The most recent guidelines from the National Academy of Sciences, Engineering, and Medicine, in 2006, recommend 15 cups of fluid for men and about 11 cups of fluid for women daily. But again, it depends. Ask your primary care physician what your hydration goals ought to be if you’re concerned about dehydration.
RELATED: The Best Times to Drink Water
8. Fact: Having a Respiratory Illness, Such as COVID-19, Makes Hydration Especially Important
If you develop COVID-19, be cognizant of potential dehydration.
“Any health issue that increases fluid excretion —?such as vomiting, diarrhea, or increased sweating from fever — increases fluid needs,” says Malkani. As the Centers for Disease Control and Prevention notes, COVID-19 may cause those symptoms and others. If you have the respiratory illness, swig more fluid than you normally would to replace what you’ve lost, advises Johns Hopkins Medicine.
Researchers also hypothesize that drinking enough water may help prevent or improve COVID-19 outcomes, as noted in an article published in November 2020 in Medical Hypotheses. That said, more studies are needed on the possible association between inadequate hydration and COVID-19 infection and severity.
9. Myth: If You’re Dehydrated, Drinking More Water Is the Remedy
Again, it depends on the situation. According to the Mayo Clinic, it’s important to see a doctor for extra medical care if you’ve had diarrhea for 24 hours or longer, feel disoriented and more tired than normal, can’t keep liquids down, or have black or bloody stool.
More moderate cases of dehydration usually require an IV of fluids, which you can get at an urgent care center, an emergency room, or the hospital, the?Cleveland Clinic notes. But if your case is severe, you may need to call 911 or visit an emergency room.
The Cleveland Clinic also notes that for mild cases of dehydration, you may benefit from a drink that contains electrolytes such as?sodium, potassium, and magnesium. This is especially important if you’ve been sweating, vomiting, or experiencing diarrhea, which leads to loss of electrolytes that are also needed to maintain adequate blood pressure.
10. Fact: Sometimes You Can Mistake Hunger for Thirst
Are you hungry or simply craving a treat? Have a glass of water before you decide. “Sometimes, it can help you actually recognize hunger signals,” Agarwal says. After that refreshment break, you may realize you were just thirsty, and not in need of a full-on snack or meal. (On the other hand, you may realize you really do want a healthy snack!)
Bonus: Drinking water before eating may help you lose weight if that’s one of your goals. One small study found that drinking about two eight-ounce glasses of water 30 minutes before each meal of the day helped people with obesity lose almost three pounds after 12 weeks, compared with a control group who didn’t drink the H2O before each meal. Authors of a study of young adults without obesity, which was published in October 2018 in Clinical Nutrition Research, wrote that drinking water before (though not after) meals increased satiety.