An Indiana family had been touring Lake Freeman, located about 80 miles north of Indianapolis, over the Fourth of July weekend. On the final day of their trip, the mother, Ashley Summers (photo at left), started complaining of a headache and other signs of dehydration, like feeling lightheaded. She reportedly drank four 500ml bottles of water in 20 minutes because she couldn’t seem to get enough to quench her thirst.

After that, Ashley went back home with her husband and two young daughters before passing out in the garage. She had severe brain swelling when she was taken to the hospital, but she tragically never recovered consciousness.

Doctors determined that Ashley had water toxicity, also known as hyponatremia, which is brought on by low blood salt levels. It can happen when a large amount of water is consumed quickly, diluting the sodium levels in the body. This exceeds the capacity of the body’s intricate organ systems, particularly the kidneys, to control the fluid balance.

Muscle cramps, soreness, nausea, vomiting, headaches, and general malaise are among the symptoms. In severe cases, the brain may swell, which may cause coma, death, seizures, confusion, and a loss of consciousness. People who frequently work outside or exercise have a higher risk of developing the fatal illness.

Learn more from the Mayo Clinic