Fatal electrolyte imbalance possible from drinking too much liquid | Fact check

Nate Trela, USA TODAY
·4 min read

The claim: Consuming too many fluids can be fatal

A July 7 Facebook post (direct link, archive link) warns against drinking too much liquid.

“Drinking too many fluids can cause water toxicity by diluting your body’s sodium and other electrolytes, which may cause your cells to swell, including the cells in your brain,” the text on the image reads. “This is a life threatening condition. If left untreated, it may cause permanent brain damage and death.”

The post was shared more than 700 times in a week.

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While rare, there are numerous case studies and reports on hospitalizations and deaths attributable to consuming too much water. The description of how the process works is correct in the post, according to medical experts.

Too much fluid can be fatal

While there is no universal reporting system, a handful of deaths in the U.S. every year are attributable to the overconsumption of fluids, said Dr. Mitchell Rosner, a UVA Health nephrologist.

The risk is highest among people participating in prolonged endurance activities, drinking faster than the body can get rid of the excessive fluid, said Rosner, who helped draft international guidelines for athletes to help ensure the safe consumption of fluids. As the Facebook post notes, when the body cannot get rid of excess fluid, electrolytes get diluted, cells can swell and swelling of the brain can prove deadly.

“When these events do occur, they are tragic and can lead to death in young, healthy individuals,” Rosner said.

Case studies and media coverage of deaths connected to water overconsumption include reports of a woman who died after trying not to urinate as part of a competition, a fraternity hazing incident and people trying to rehydrate after consuming MDMA and sweating profusely.

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How much fluid is safe for someone to consume depends on a number of factors, including activity levels, a person’s health, and temperature and humidity. The Centers for Disease Control and Prevention warns that people should not consume more than 48 ounces of water in an hour, while some doctors say not to consume more than one liter of fluid per hour.

Rosner said in many cases, drinking to match your level of thirst when involved in significant physical activity is a good guideline. Katherine Basbaum, a registered dietitian with UVA Health, said ideally people would drink water before they are thirsty but also need to be aware of warning signs of overconsumption of fluids.

Symptoms, which can be similar to the more common risk of dehydration, include headaches and nausea. Rosner said one of the biggest physical warning signs of water overconsumption is if those symptoms start and a person’s weight is the same or higher than when they began an activity. If a person is dehydrated, their weight would drop. Basbaum also noted that a dehydrated person’s urine, if they can even produce it, tends to be darker and stronger smelling than normal.

But the most important warning sign of overconsumption of water is if someone begins having confusion and an altered mental state, which could indicate brain swelling. In that event, Basbaum and Rosner agreed that seeking prompt medical attention is critical. For more minor symptoms, consuming salty snacks and pausing fluid intake are good first steps.

There are several terms – some medical, some colloquial – that are used online for the electrolyte imbalance that comes from overconsumption of fluids, including water toxicity, water intoxication, hyponatremia, water toxemia and hyperhydration. While they may have different precise definitions and causes, they all describe the risk posed by cells swelling and the dilution of sodium and other electrolytes in cells, Rosner said.

USA TODAY reached out to the user who shared the post for comment but did not immediately receive a response.

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This article originally appeared on USA TODAY: Overconsumption of water can kill you in extreme cases | Fact check