Dehydration is a common cause of fatigue and premature aging.

According to a recent survey many people do not drink the eight glasses of water a day recommended by the World Health Organisation. Water is an essential nutrient in every function of the body. In fact, without water we would probably not survive more than five days.

Almost three quarters of our body is made up of water. Even our bones consist of one third water. Water in our body is used to digest food, regulate the body's temperature, lubricate the lungs and skin and wash away wastes. The intestines, kidneys, bladder, skin and lungs all need water to get rid of toxins.

Signs that you might not be getting enough water include, unexplained headaches, fatigue, irritability, restlessness, difficulty sleeping, dry skin, constipation and a dull backache that is not relieved by rest.

A lack of water can also cause weight gain and swollen hands or feet. When you don't get the water you need, your body retains the water it has.

Not drinking water because you're not thirsty is a common mistake. By the time you feel thirsty, you are probably already suffering from some degree of dehydration. According to scientists thirst is an evolutionary development designed to alert us to severe dehydration.

Substituting tea, coffee, soft drinks or alcoholic beverages for water is counter-productive as they make the body eliminate more water than it gains. Drinking more water needn't mean more visits to the bathroom. According to Dr. Batmanghelidj, author of "Your Body's Many Cries for Water", your kidneys will adapt.

A hot or dry climate, exercise and a high salt diet increases our need for water. In Bermuda, we tend to absorb sodium from the ocean and should compensate by drinking more water.

According to Henry B. Lin, the author of Chinese Health Care Secrets, the ancient Chinese advise that we drink a cup of water as soon as we get up in the morning, but at least fifteen minutes before breakfast. (Drinking too close to meals dilutes our digestive juices causing indigestion).

"The ancient Chinese hold that this cup of water, called Holy Morning Water in ancient Chinese classics, is necessary to wash away the yin-qi (deadly spirit) that has accumulated in the body during sleep.

With the extra yin-qi washed away, yang-qi (the lively spirit) begins to produce itself until a new balance is struck between the yin and the yang. As a result, we will feel doubly invigorated during the day," explains Mr. Lin.

So drink up, it's free -- at least it used to be!