How much water is too much?

Water intoxication sounds like an oxymoron. How can water, a refreshing drink that everybody needs for sustenance, cause intoxication? Drinking enough water certainly is a key component of a healthy lifestyle. But drinking too much water leads to serious health consequences — swelling of the brain, brain injury, and ultimately stroke — leading to disability or even death.

It is not only the amount of water consumed that causes overload — water toxicity is caused by drinking too much water too fast. Most people who overdose on water are not aware of the consequences. So the obvious question is — why would anyone drink excessive amounts of water too fast? There are, in fact, some circumstances that set the stage for water overdose.

Water Games
These activities often seem silly or harmless to people. Preschool aged children and older kids may think it is funny to challenge each other to drink large amounts of water quickly. Water overload has been responsible for incidents of brain damage and death in children, teenagers and young adults who play games involving exaggerated fluid drinking or who use rapid consumption of excess water or fluid. The rapid consumption of large amounts of water overwhelms the body’s natural ability to maintain normal fluid balance. This causes excess fluid to enter the brain, resulting in brain swelling, which causes sudden unexpected loss of consciousness, seizures, or flaccid weakness of the body.

Health Cleanse
The idea of drinking water because it is pure and devoid of calories is popular among health enthusiasts. But the advice to “drink more water”, doesn’t apply to all. The ideal amount of fluid consumption for an average person should be between 9-12 cups per day. People who already consume enough water need not drink more. In general, thirst is a reliable indicator of the body’s water requirements. Some health conditions such as diabetes and kidney disease require a consultation with a dietician or physician to set guidelines for fluid intake.

Athletics
It is normal for athletes to drink fluid in order to replenish and cool off during and after a training session and it is important for the body to stay hydrated during exercise. However, in the setting of extreme physical exertion, thirst may not be the best guide. Devoted athletes who work out beyond moderate levels should obtain professional guidance regarding appropriate fluid replenishment.

How does water overdose cause brain damage and stroke?
When the body takes in extreme amounts of fluid, the excess water literally flows into the brain cells. This causes brain tissue compression and lack of normal function. Regions of the brain subsequently lose their normal calcium and sodium concentration and begin to function abnormally. Some brain cells may die from physical compression, and some from the electrolyte and water imbalances. This condition — hyponatremia is very difficult to medically treat because it progresses so rapidly and the damage is so severe. Severe sodium and water imbalances affect a specific area in the brainstem called the pons, causing a syndrome called central pontine myelinolysis or locked-in syndrome.

— Source: www.stroke.about.com