In 2007, a 28 year old woman from California, United States joined a water-drinking contest on the radio entitled "Hold your Wee for a Wii". After drinking 6 liters of water for 3 hours, Jennifer Strange vomited, went home with a terrible headache, and died from so-called water intoxication.
Another tragic incident happened in 2005. A 21 year old man was forced to drink excessive amounts of water between rounds of push-up in a hazing rite by a fraternity in California State University in the US. He was left dead in a cold basement.
A 2005 study in the New England Journal of Medicine found that close to one-sixth of marathon runners develop some degree of
hyponatremia, or dilution of the blood caused by drinking too much water.
Hyponatremia comes from the Latin and Greek words which means "insufficient salt in the blood." Specifically it means having a blood sodium concentration below 135 millimoles per liter, or approximately 11.37 milliliter per gallon. The normal concentration lies between 135 and 145 millimoles per liter. Severe cases of hyponatremia can lead to water intoxication, an ilness whose symptoms include headache, fatigue, nausea, vomiting, frequent urination, and mental disorientation.
Our kidneys control the amount of water, salts and other solutes eaving the body by filtering blood through kidney's millions of tubules. When a person drinks too much water in a short period of time, the kidneys cannot flush it out fast enough and the blood becomes waterlogged. and then the excess water will enter into cells and into brain cells and neurons and since the brain cells are tightly packed in our skull, there will be almost zero room to expand and swell inside the skull. Thus, brain swelling can be dangerous. It can manifest seizures, comma, respiratory arrest, brain stem herniation, and death.
Sources:Coco Ballantyne.
Strange but True: Too Much Drinking Water can Kill.http://www.scientificamerican.com/article.cfm?id=strange-but-true-drinking-too-much-water-can-kill
Bato Balani. ISSN 0117-7079 VOL.28 No.4 SY 2008-2009