Staying hydrated is crucial to regulate the digestive system, ensure healthy brain function, keep a regular body temperature and the heart beating normally.
Our mental health, physical endurance and energy are all boosted when we are hydrated and water makes up about 70-80 percent of the brain, heart, kidneys and lungs, according to federal data.
Recommendations for how much to drink vary. Some past studies say the average adult will get enough water if they drink about 11.5-15.5 eight-ounce cups a day and a suggestion for eight eight-ounce glasses has been widely shared for decades.
But experts stress that staying hydrated is a much more personal endeavor.
“It’s a one-size-fits-all that doesn’t fit all,” Tamara Hew-Butler, associate professor of exercise and sport science at Wayne State University, said in a statement. “It’s not going to work for everybody in all situations.”
open image in galleryA person with a larger body mass needs more water, past research from the University of Michigan shows. The same is true for people who have more muscle mass. That’s because water makes up over 75 percent of muscle.
People with more muscle mass have more water in their bodies and need to drink more to maintain their fluid balance, Dr. Stavros Kavouras, a professor and director of the Arizona State University hydration science lab, told The New York Times.
People who work out more or live in hotter climates need to replace the water they lose in sweat more than people who don’t.
When sweating, the body also sheds critical minerals called electrolytes that help nerves and muscles work. Electrolytes include sodium, potassium, calcium and other substances that also help the body stay hydrated, The Ohio State University says.
But you don’t really need electrolytes unless you’re sweating excessively or replenishing lost fluids, said Kavouras.
That’s the case even for people exercising for 30 minutes to an hour. “You’ll complete your electrolyte needs by eating regular foods,” he also told TIME.
open image in galleryBut while hydration looks different for everyone, signs of dehydration are typically universal. Watch out for dark-colored urine, extreme thirst, dizziness, fatigue, dry mouth, headache, a high heart rate, low blood pressure and muscle cramps, according to the Cleveland Clinic.
And severe cases can lead to urinary and kidney problems, heat injury, seizures and stop the heart from pumping enough blood throughout the body, the Mayo Clinic warns.
That’s concerning because 75 percent of Americans aren’t drinking enough water.
“Ideally, your urine should be a pale, straw yellow color,” Gabrielle Judd, a dietitian at Johns Hopkins Bayview Medical Center, said in a statement. “If it’s deeper yellow or golden, you’re likely dehydrated.”
Drinking water is the fastest way to cure dehydration, working in just minutes – although some foods can help too. Celery, cucumbers and romaine lettuce are made up of 95 percent water, Nancy Oliveira, a registered dietitian at Harvard-affiliated Brigham and Women’s Hospital, said.
“Other fruits and vegetables, such as green grapes, peaches and corn, are in the [70-90 percent] water range,” she explained in a blog post.
open image in galleryHowever, people should take caution. There is such a thing as too much water, too.
Drinking too much water can put pressure on your brain, the Cleveland Clinic says. It can be fatal in some cases.
This is called water intoxication, which has been seen in people who drink over 100 liters of water in just an hour of two. It can be hard to tell if you’re suffering from water intoxication, but there is one sign.
“You may be drinking too much water if your pee is colorless or clear,” the Cleveland Clinic notes.