Experts debunk 9 hydration myths

Woman with water bottle
How much water do you really need to drink? (Getty Creative)

With temperatures rising, you might be making more of an effort to stay hydrated and keep that giant Stanley tumbler filled to the brim. Maybe you’re even looking to jump on the “sexy water” bandwagon by adding ice, fruit and various supplements to make your H20 intake more fun. Whatever it takes, right?

But there’s more to healthy hydration than cute water bottles and TikTok trends. Dehydration — especially if you’re hitting up a pool party or boozing by the beach under a blazing sun — is a health condition that can wreak havoc on your body if it’s not addressed quickly. It also might be the underlying cause for symptoms — some of them serious — you might be attributing to something else.

Given the level of confusion out there — like, how much water is enough, how do you know if you’re dehydrated and is that iced coffee making it worse? — we turned to health experts to debunk the most frequent hydration myths they encounter. Here’s what you need to know.

How much water you should imbibe daily depends on your individual needs. According to Dr. Dana Cohen, medical adviser for Cure Hydration, a good goal is to drink approximately half your weight in ounces of water each day.

But body weight isn’t the only thing we should consider, Cohen says. You may need more water based on your exercise and level of activity, the amount you sweat, your age, any medications you’re taking, your diet and the heat and humidity in your environment. For example, if your diet is high in water-based foods like fruit, smoothies or soups, you may not need as much water.

Nope. Along with fruits, vegetables and other water-based foods such as celery, other beverages, with the exception of those that contain alcohol, can help hydrate you. In fact, some studies claim that milk is more hydrating than water.

The caffeine in coffee is a mild diuretic, which means it increases urine production. Urinating more often can lead you to lose water, which your body needs for hydration. However, since you take in more liquid than you lose while drinking coffee, it doesn’t have enough of an effect to lead to dehydration, and can actually count towards your hydration goals for the day.

That said, coffee shouldn’t be your only source of liquid. Make sure to drink other fluids (like water) and to monitor your caffeine intake, which, in excess, can cause other health issues. The United States Department of Agriculture’s dietary guidelines say to limit your daily intake to around 400 milligrams of caffeine, or about four cups of coffee.

When functioning properly, our bodies are made of about 55% to 60% water. When we are hydrated, our cells have enough water inside of them to function properly, Cohen says.

When these cells are not properly hydrated, they are not operating efficiently. That’s because our bodies are spending their resources trying to warn us about our hydration levels. That headache or fatigue you feel when you are dehydrated is a sign your body is expending energy on this warning system, and pulling resources from other important functions.

Being hydrated isn’t just about getting enough water, however. It also means that our bodies are in homeostasis, that is, our mineral, vitamin and fluid levels are balanced.

While one of the first signs of dehydration is increased thirst, some signs may be easy to misread as symptoms of something else. These signs include dizziness, weakness, headache, dry skin, dry mouth or fatigue, says Cohen.

One major indication that you’re dehydrated, Cohen adds, is that your urine may appear amber-colored. If you use the bathroom, you may also notice a smaller amount of urine than usual.

Not necessarily. The longer you go without water, the more you risk serious symptoms of dehydration. More severe dehydration, Cohen warns, can present with anuria (no urine output), dizziness that makes it difficult to stand or walk normally, low blood pressure, fast heart rate, fever, lethargy and confusion. In severe cases it can lead to seizures, shock or coma — symptoms that require immediate medical attention.

You’re constantly refilling your water bottle — but somehow you still feel thirsty. There could be an underlying issue driving this thirst, such as anemia, having your period or being diabetic. If you feel like you are properly hydrating but are thirstier than usual, speak to a doctor. Certain medications (such as those for allergies or motion sickness) can also give you a dry mouth sensation that isn’t necessarily associated with not drinking enough water.

You may have seen electrolyte drink packets, drops or even beverages like Gatorade that promise to boost your hydration. But are they really better than drinking plain water?

It depends. Electrolytes are minerals in your body fluids — such as sodium, potassium, chloride and magnesium — that are essential for various bodily functions, such as maintaining hydration. We lose electrolytes in sweat and excrete them in urine.

However, on a typical day of sweating, we don’t need to think about our electrolyte levels. That’s because most adults get enough electrolytes through our food intake. says Dr. Jo Anna Leuck, a physician at Burnett School of Medicine at Texas Christian University.

You may need to boost your electrolytes, however, if you are doing intense exercise (such as a workout for more than 75 minutes) or spending time in the heat, as plain water may not be enough to maintain hydration. It’s also important to supplement electrolytes, Leuck says, if you had an illness, such as a stomach flu, that prevented you from getting them through your diet.

That said, it’s important not to overdo electrolytes too. Consuming an excess of electrolytes can put strain on your kidneys. Too much sodium, for example, can cause dizziness, vomiting and diarrhea, as well as seizures and loss of muscle control.

Yes, you can be overly hydrated — and it can cause major problems. Water toxicity happens when someone drinks water too fast, throwing off their body’s electrolyte balance — and some people have even died from it. As Cohen says, “supersizing your Stanley Cup may actually flush essential electrolytes out of your system instead of properly hydrating you.”

Consuming excessive amounts of plain water can lead to a dilution of sodium in the bloodstream known as hyponatremia. That, Cohen says, “can cause water to move into cells — including brain cells — potentially resulting in swelling, increased intracranial pressure and, in severe cases, can potentially lead to seizures.”

This is why it’s a bad idea to try and flush out your body with water, or to drink excessively when doing heavy endurance exercise. It’s always best to follow your body cues, such as thirst, to guide your water intake.