How much water should I drink?

Q: How much water does the average person really need to drink? And is there such a thing as too much?

If you don't sip on a 64-ounce Stanley cup all day, are you still alive? Hydration is having a moment again: TikTok videos with the #watertok hashtag now have more than a billion views.

Whether you drink from a trendy cup or from a plain old glass, there is no one-size-fits-all answer to the question of how much water you should drink in a day. The closest the United States has come to a water consumption recommendation comes from the National Academy of Medicine, which in 2004 reported that healthy men usually stay hydrated if they drink at least three liters (almost 13 cups) of water per day, and that women tend to be hydrated if they drink at least 2.2 liters (just over nine cups) per day, not counting water they consume through food.

But these guidelines shouldn't be taken as gospel, experts say.

“Most people will be fine even if they fall below that recommendation,” says Dr. Siddharth P. Shah, a nephrologist at the Hospital of the University of Pennsylvania who specializes in hydration and electrolyte balance.

When should I drink water and how much?

Water is of course crucial to our survival. It helps us eliminate waste, maintain blood pressure, regulate body temperature and more.

Some people need more water than others. People who are particularly active — who have physically demanding jobs or who exercise a lot — lose more water through sweating and will need to compensate by drinking extra water, said Dr. George Chiampas, an emergency medicine specialist at Northwestern Medicine and chief medical officer. employ. for the United States Soccer Federation.

People may also need to drink more if they live in a warm climate, have a larger body or a lot of muscle mass, have loose stools, are pregnant or breastfeeding, or have had kidney stones or recurring urinary tract infections, experts said.

Over the course of life, a person's water needs also change. Normally, as people age, they lose muscle and gain fat, said Dr. Shah. Because fat contains less water than muscle, people generally need to consume less water as they age to maintain healthy tissues.

Yet some older adults still don't consume as much water as they need, said Dr. Shah, because the bodies of older people – especially: research suggests people over 60 years old – are not very good at detecting thirst. The level of dehydration “that would make you thirsty at age 40 may not make you as thirsty at age 80,” he explained.

If you're thirsty, you're probably dehydrated and should drink water, said Dr. Alysia Robichau, a family physician and sports medicine physician at Houston Methodist.

There may also be more subtle signs of dehydration, such as feeling constantly cold or having dry skin, said Dr. Robichau. People who are acutely or chronically dehydrated may also have headaches or dry eyes, she added.

Because people don't drink water while they sleep, “most people wake up and they're already dehydrated,” Dr. Chiampas said. It's generally a good idea, he said, to start the day with a glass.

It's okay to add flavorings to your water or drink carbonated water, said Dr. Robichau, but she cautioned that coffee and other caffeinated drinks may not be as hydrating as decaffeinated drinks. Drinking a caffeinated beverage, especially if you don't drink it regularly, can reduce the kidneys' ability to absorb water, causing you to lose extra water through the urine. Alcoholic drinks are also dehydrating.

Keep in mind that you can also get water from food. Some fruits and vegetables, such as watermelon and celery, are made up mostly of water, Dr. Shah said. The National Academy of Medicine estimates that, on average, people get 20 percent of their water through food.

It's unlikely that most people drink too much water, but it is possible, especially among endurance athletes who drink a lot of water quickly, Dr. Chiampas said. Doing so can upset the body's sodium and potassium balance and lead to potentially fatal water intoxication.

The Centers for Disease Control and Prevention advises drinking no more than 48 ounces of water per hour. Also keep in mind that there are probably no health benefits to guzzling tons of water.

“There are a lot of excessively large water bottles being carried around by people these days,” said Dr. Shah. “But the vast majority of people don't need to drink too much water.”