(NEXTAR) – 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.

One such case involved a 35-year-old woman in Indiana who unexpectedly died last month after consuming a large volume of water in a short amount of time, leading to low sodium concentrations in the blood, brain swelling and ultimately death, medical experts believe.

“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 Indiana 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.

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.

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

In Summers’ case, it’s generally believed that her excessive thirst was the result of dehydration after spending the day outdoors. The amount of water in her system likely created an imbalance, diluting the amount of sodium in her blood and forcing her body to attempt to compensate.

“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.”

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.