By Mary Jo DiLonardo
WebMD Feature
You've heard it a million times. When it's hot outside or you're exercising, drink water -- lots and lots of water. It's how your body stays hydrated.
But drinking an extreme amount of water in a short time can be dangerous. It can cause the level of salt, or sodium, in your blood to drop too low. That's a condition called hyponatremia. Low sodium levels combined with large amounts of water can lead to water intoxication, which is not only harmful, but you can die.
"These are very isolated cases, and this is extremely rare," says Sharon Bergquist, MD. She's an assistant professor of medicine at Emory University School of Medicine in Atlanta. "More people by far and away are dehydrated, [rather] than having a problem with over-hydration."
What Is Water Intoxication?
If you drink a bottle of water here and there when you exercise or when you're hot, you’ll be fine. Where you run into problems is drinking way too much too fast.
"Young, healthy people don’t normally [get hyponatremia] unless they drink liters and liters of water at once, because your kidneys can only [expel] about half a liter at most an hour," says Chris McStay, MD. He's an emergency medicine doctor at the University of Colorado School of Medicine. "You're drinking more than your kidneys can pee out."
The issue boils down to sodium levels. One of sodium’s jobs is to balance the fluids in and around your cells. Drinking too much water causes an imbalance, and the liquid moves from your blood to inside your cells, making them swell. Swelling inside the brain is serious and requires immediate treatment.
Causes
When you work out, you sweat out sodium, which is an electrolyte. These help maintain normal fluid levels in your body. People drink water or sports drinks to get those levels back in balance. Think of football players at practice on a hot summer day.
Even babies can have issues. Their bodies are so tiny that they can't handle lots of water. That's why doctors say infants should drink only milk or formula.
Then there are the cases like hazing rituals and publicized contests where people drink large amounts on purpose.
Symptoms and Treatment
The warning signs of water intoxication look a lot like the symptoms of heatstroke and exhaustion. You might be hot, have a headache, and just feel crummy. Other early symptoms can include diarrhea, nausea, and vomiting.
"If you see someone like that, pull them aside, put them in the shade, and talk to them," McStay says. It’s often hard to tell the difference, he says, between water intoxication and heat exhaustion, “unless you know they drank 6 gallons of water."
If you don't get help right away, the condition can quickly lead to swelling in the brain, seizures, and coma. Get to an emergency room as soon as you can. Doctors there can inject concentrated salt water to ease swelling and reverse problems.
source : Can I Die From Drinking Too Much Water?
