Thursday, December 2, 2010

Your Need for Water

Since water is so much a part of our very existence, we need to keep our bodies well supplied. Though a person may survive as much as eighty days without food, few can last longer than about ten days without water. With a very small drop from normal water content, you quickly feel thirsty. Even a 1- or 2-percent deficiency of water can be distressing or painful. Just 5 percent causes skin shrinkage, dried-out mouth and tongue, and hallucinations begin. A 15-percent loss is usually death-dealing.

Your body is constantly losing water. In addition to the two pints normally lost through the skin and breath, another three pints or more may be eliminated through your kidneys and bowels. Water lost by sweating, and even by tears, has to be added to the normal total of five or six pints that must be replaced each day to maintain your body’s fluid balance.

Does this mean that you have to drink three quarts of liquid every day? Not unless you are sweating heavily. Actually, about a third of the water you need comes from eating “solid” food, which is often mostly water. Even bread is about a third water. Interestingly, your own body cells manufacture nearly a pint of water (H2O) chemically as they use oxygen (O) to burn the hydrogen (H) in your food as fuel.

Thus you may need to drink only five or six glasses of liquids such as milk, coffee, juice or water directly each day. But even though water is among the most abundant substances on earth, supplying enough drinkable water is a major undertaking. Since it can dissolve so many different substances, water is not always safe to drink without purification.