Drinking too much water can lead to a potentially fatal condition called water intoxication or hyponatremia, where excess water dilutes sodium levels in the blood, causing cells—including brain cells—to swell. This swelling can lead to symptoms ranging from headache, nausea, and confusion to seizures, loss of consciousness, and death in severe cases
. There is no exact amount of water that will cause death because it depends on factors like body weight, kidney function, and the rate of water intake. However, the kidneys can typically process about 1 liter of water per hour safely. Consuming significantly more than this—especially over several hours—can overwhelm the kidneys and increase the risk of water intoxication
. According to the American Chemistry Society, drinking around 6 liters of water in a short period can be lethal for a 75 kg (165 lb) person
. There have been documented cases of death from drinking excessive amounts of water quickly—for example, a woman died after drinking 2 liters in 20 minutes
. In summary:
- Kidneys can safely process about 1 liter of water per hour.
- Drinking more than this over several hours can cause hyponatremia.
- Around 6 liters consumed rapidly can be fatal in an average adult.
- Symptoms of water intoxication include headache, nausea, confusion, seizures, and potentially death.
To avoid risk, it is best to drink according to thirst and not force excessive water intake in a short time
