The problem is that drinking all that pure water will flush out all the salt and electrolytes in your body, causing brain swelling, and leading to seizures, coma or even death. Ever taste your own blood? Its salty. Your body needs salt in your system to maintain its balance- as everyone knows- eating too much salt is bad, now know that too little salt can be fatal.
The condition is known Hyponatremia. And occurs when a person loses a large amount of sodium. Its usually caused by consuming large amounts of water. Its the opposite of dehydration.
As the blood becomes increasingly diluted, water moves out of the bloodstream and into cells, which swell. The swelling of the brain is responsible for the symptoms of severe hyponatremia -- nausea, confusion, seizures and coma. If pressure inside the skull increases enough, the base of the brain is squeezed downward through where connects it to the spinal cord, causing death.
Read the sad story here:
The woman had earlier shown photographs of her children whom she was hoping to win the prize for. The prize, a computer game console sells for about $250.
If someone has drank too much water and starts complaining of nausea, headaches let the person drink some Gatorade that will help bring up the person's natural levels of potassium, citrate and sodium chloride. Or get them to eat a banana which has plenty of potassium inside.
Whatever you do do *NOT* let them drink more water, tea, coffee, or alcohol. These are all diuretics and will make the problem worse. They also contain none of the electrolytes you'll be in need of.
If the person starts vomiting- better call an ambulance straightaway! And explain that the victim has drunk too much water- as most of the time, its the other way round, ie. too little water; dyhydration victims also manifest the same outward symptoms- nausea, confusion, fatigue.