Is it possible to drink too much water?

Drinking too much water can lead to hyponatremia and water intoxication, which can be fatal, according to Scientific American. Hyponatremia dilutes sodium out of the bloodstream and pushes it below safe levels.

Severe cases of hyponatremia may cause water intoxication, according to Scientific American. Symptoms of water intoxication can range from headache to mental disorientation, and if it comes on too quickly, it can cause brain edema and death. Several reported incidents of death from water intoxication were attributed to hazing and water drinking contests. Runners often experience some effects of hyponatremia due to their frequent intake of water during events.