Drinking Too Much Water — Water Intoxication — Can be Deadly. Do I Need to Worry?

While staying hydrated is a crucial part of health and survival, it is possible to overdo it.

Water poisoning, known as water intoxication, is a genuine thing that can be deadly. Awareness of water poisoning has recently increased due to several events that have called into question how much water people should drink daily. What has been happening, and how concerned should you be about water intoxication?

What has been happening?

Several recent headlines involving hydration have raised some eyebrows. Recently, Vanity Fair did a behind-the-scenes look at Marvel’s “secrets” and included a few tidbits about Chris Pratt being cast as Star-Lord in Guardians of the Galaxy. The initial story reported that Pratt’s nutritionist, whom he worked with for the movie, had him drink 220 glasses of water daily. “I was peeing all day long, every day,” said Pratt. “That part was a nightmare.”

That information drew a lot of attention, with toxicologist Dr. Ryan Marino going viral on X, formerly known as Twitter, to call additional attention to it. “This is not possible, and it is literally how you get water poisoning, which is really, really dangerous to do cause it’s really, really bad,” wrote Marino. “He absolutely did not do this, and you should not do this, too!”

The story was edited later to say: “Marvel also introduced Pratt to nutritionist Philip Goglia, who increased Pratt’s caloric intake to 4,000 a day, plus one ounce of water for each pound the actor weighed.”

The story comes only weeks after news broke that Ashley Summers, an Indiana mom, died after drinking too much water too fast. “At one point during the day, she started getting a bad headache,” said her brother, Devon Miller, to Good Morning America. “So, she was drinking a lot of water.” According to Miller, Summers drank the equivalent of four 16-ounce water bottles in 20 minutes. Later, she collapsed in her garage and died.

Should I worry?

Water intoxication is severe and can end up being fatal. Medically, it is known as hyponatremia. Hyponatremia happens when a person ingests so much water the electrolytes in their blood become diluted, said Dr. Eric Adkins, emergency room physician at the Ohio State University Wexner Medical Center. In drinking too much water, “people are really worried about sodium, which is an electrolyte,” said Adkins.

Among other things, sodium helps to control your nerves, muscles, and blood pressure, as well as balances the body’s fluids, according to the National Kidney Foundation. If your sodium levels drop too low, below 135 milliequivalents per liter, extra water can enter your cells, causing swelling. 

According to the U.S. National Library of Medicine, that can lead to symptoms including convulsions, headache, confusion, muscle weakness, vomiting, and nausea. People can experience brain swelling, seizures, or death, said Dr. Andrew C. Kline, an emergency physician at Corewell Health.

While doctors say water poisoning isn’t common, it can still happen. “We’ve seen so many people over the years who have done things like this, often as an attempt to ‘flush out toxins’ or as part of a special training or diet routine,” said the chair of emergency medicine at Rutgers New Jersey Medical School, Dr. Lewis Nelson. “It inevitably leads to significant harm.”

However, your body can typically handle more water than usual, said sports medicine specialist and orthopedic surgeon at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, Dr. Natasha Trentacosta. “Normally, drinking large amounts of water can be managed by the natural ability of our bodies to regulate water excretion through the combined efforts of the pituitary gland, kidneys, liver, and heart,” she said. 

Kline also says it’s “rare” for someone to have excess water that would cause serious problems accidentally. “When these situations do occur, it is usually intentional,” he said and cited endurance athletes and competitive runners trying to get well hydrated. This means you are unlikely to get water poisoning by accidentally drinking an additional water bottle during your daily routine. 

What can I do to lower my risk?

You can do a few things to lower the risk of water poisoning, including keeping tabs on the amount of water you regularly consume and being aware that you can get sick from having too much water, says Adkins. 

Listening to your thirst cues is critical, says Kline. “For a majority of patients, allowing thirst to guide your water consumption is a safe bet,” Adkins says.

The U.S. National Academies of Sciences, Engineering, and Medicine recommends women aim to have around 11.5 cups of fluids — from water and food — a day, and men should aim to have about 15.5 cups daily. However, your body composition, your activity, how often you sweat, and the temperature around you can also influence how much you should consume, says Nelson, making it difficult to say you shouldn’t have more than a set number of glasses of water per day.

Adkins says an excellent way to measure hydration is by monitoring your urine. “You want it to be light yellow to clear, but you shouldn’t be going to the bathroom every 15 minutes,” he said. “The body can’t keep up with that.”

The key takeaway

Doctors said you shouldn’t live in fear of overhydration but be aware that water poisoning can happen. 

“Anything in excess is a problem,” says Nelson. “Even water is toxic if you have too much.”