Water makes up 55% to 78% of the human body depending on the body size. As recommended by health experts, approximately 2 to 3 liters of water are required in minimum to maintain proper hydration in the body. But have you ever heard of fatal water overdose?
According to a video, “How Much Water Can Kill You?” released by the American Chemistry Society, it takes about 6 liters of water to kill a 165-pound (74.8 Kg) person. Having known how much water will kill you, would you consider drinking this much of water a day?
Drinking too much water makes a blood become dangerously diluted of salts and this causes a condition called hyponatremia – having abnormally low-level of sodium concentration in blood. Severe cases of hyponatremia can lead to water intoxication, which some of its main symptoms include headache, fatigue, nausea, vomiting, frequent urination and mental disorientation.
According to Scientific American, there has been several cases of death by water, of which some of them are:
- A 28-year-old California woman died after competing in a radio station’s on-air water-drinking contest. After downing some six liters of water in three hours in the “Hold Your Wee for a Wii” (Nintendo game console) contest, Jennifer Strange vomited, went home with a splitting headache, and died from so-called water intoxication.
- In 2005 a fraternity hazing at California State University, Chico, left a 21-year-old man dead after he was forced to drink excessive amounts of water between rounds of push-ups in a cold basement.
- Club-goers taking MDMA (“ecstasy”) have died after consuming copious amounts of water trying to rehydrate following long nights of dancing and sweating. Going overboard in attempts to rehydrate is also common among endurance athletes.
- 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.
The kidneys control the amount of water, salts and other solutes which also includes the process of filtration and reabsorption. However, 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. As a result, excess water leaves the blood and enters the cell that cause them to swell.
Most cells can resist the swell caused by excess water as they are embedded in flexible tissues, but for brain cells, it is quite the opposite – the situation can be catastrophically fast as they are compactly packed inside a rigid boney case with no room to expand or swell. Thus, brain edema, or swelling, can be disastrous.
“Rapid and severe hyponatremia causes entry of water into brain cells leading to brain swelling, which manifests as seizures, coma, respiratory arrest, brain stem herniation and death,” explains M. Amin Arnaout, chief of nephrology at Massachusetts General Hospital and Harvard Medical School.
Joseph Verbalis, chairman of medicine at Georgetown University Medical Center told Scientific American, “Most cases of water poisoning do not result from simply drinking too much water, it is usually a combination of excessive fluid intake and increased secretion of vasopression (also called antidiuretic hormone). Produced by the hypothalamus and secreted into the bloodstream by the posterior pituitary gland, vasopressin instructs the kidneys to conserve water. Its secretion increases in periods of physical stress—during a marathon, for example—and may cause the body to conserve water even if a person is drinking excessive quantities.”
As for my opinion, I think it is completely safe, provided you split all the 6 liters of water into a certain equal amount and drink at different intervals of the day. For example, drinking 500 ml of water for every 2 hours would take 24 hours to finish all up and it certainly will not kill you.
So answering your question: How much water does it take to kill you? Well, just about 6 liters, but also only if you drink all up in a short period of time, otherwise it is completely safe.
- Source: Scientific American
- Video: American Chemistry Society