Editor’s note: On Aug. 28, 2023, the Tippecanoe County Coroner said it found Ashley Summers’ death was accidental and not related to water toxicity. This story, originally published on Aug. 12, has been updated to include the new information from the coroner’s office.

(NEXSTAR) – Staying properly hydrated is essential for keeping the body functional and healthy. But too much can be detrimental, and, in very rare cases, lead to death.

Medical experts originally believed that was the case with a 35-year-old Indiana woman who unexpectedly died last month. Experts said her death came after consuming a large volume of water in a short amount of time, potentially leading to low sodium concentrations in the blood, brain swelling and ultimately death.

“A condition happens in your body if you drink too much liquid that has no electrolytes in it, which is water, which causes hyponatremia, which is low sodium,” Monica Gandhi, M.D., a professor of medicine at the University of California in San Francisco told NewsNation last week.

“If you have low sodium, you can get many conditions, but it’s really brain swelling that led to the death in this case. It’s a very sad case,” she said.

Ashley Summers, the woman who died last month, had reportedly claimed to be feeling dehydrated after spending the day with family at a lake near the town of Monticello. She drank four bottles of water in about 20 minutes, and collapsed in her family’s garage.

Summers was later pronounced dead at a hospital, where doctors informed her husband that acute water intake was the cause.

However, after “a complete medical record review, various interviews, law enforcement report review, 911 calls, an ambulance report review, laboratory tests and analyses, and a forensic autopsy,” the county coroner ultimately came to a different conclusion.

An electrolyte imbalance was to blame for Summers’ death, the coroner said, but the cause of the imbalance was not related to water toxicity. Alcohol consumption and heat stroke may have played a role, the coroner’s office said, but the exact cause is unknown.

“The volume of water that was reported to have been consumed is well below the typical water consumption volume reported in cases of pure water intoxication,” the coroner said in a press release on Aug. 28.

Death by “water intoxication,” also called “water toxicity,” is believed to be rare in people with no underlying medical conditions. But a number of those underlying conditions — whether brought on by medications, or overproduction of certain hormones — can increase the risk of hyponatremia, usually by interfering with kidney processes or causing the body to retain water, according to the Mayo Clinic.

“That extra water has to go somewhere, and it goes into your tissues. And the tissue we really worry about is the brain, and it causes brain swelling,” Jared Fialkow, a nephrologist and doctor of osteopathic medicine at Hendricks Regional Health in Danville, Indiana, told Nexstar’s WXIN. “So if you’re doing it too quickly, that’s what often happens in water intoxication.”

Polydipsia, a condition that can be triggered by certain medications or diabetes, among other factors, can also cause excessive thirst, Gandhi said.

Detecting the early symptoms of water intoxication can be life-saving, according to multiple studies made available online by the National Institutes of Health. These symptoms can include nausea, headaches, vomiting, confusion, disorientation, and even psychosis, and should be communicated immediately to a health care provider. More severe cases of hyponatremia may require hospitalization or prescription medication, according to the Cleveland Clinic.

Preventative measures, as usual, are the best way to avoid a dangerous outcome.

The daily recommended intake of fluids is around 15.5 cups for men and 11.5 cups for women, according to the Mayo Clinic and Harvard Health, though around 20% of that usually comes from food, the former notes.

The amount of fluids a person needs may also depend on the level of activity that person is exerting, with more activity usually necessitating more fluid. But anyone engaging in strenuous or especially sweaty activity should ingest fluids throughout, and not “all at the very end,” according to Fialkow.

He also told WXIN he recommends drinking “something that has a little bit of sodium, a little bit of an electrolyte solution” to prevent sodium imbalances, but not just necessarily a “straight” sports drink that contains a lot of sugar.

“If you’re thirsty, 8 to 12 ounces every 20, 30 minutes … should be fine,” Fialkow said.