by Susanna Perkins

Created on: August 31, 2009

Dehydration is more than just feeling thirsty after exercising. While mild dehydration is simply a nuisance, severe dehydration can cause brain damage, kidney failure, coma and death. Knowing the causes of dehydration can help you prevent it.

Dehydration occurs when we don't have enough fluid for our bodies to function normally. An average adult loses about 10 cups of water a day through breathing, sweating, and waste removal. Along with fluid, electrolytes - minerals such as sodium, potassium and calcium - are eliminated as well. Illness, exercise and environmental factors can speed fluid loss and make it difficult to rehydrate. However, awareness of what causes dehydration and some planning ahead of time can help you stay well hydrated and healthy.

If you have a fever, vomiting or diarrhea, your fluid loss is greater than normal. A healthy adult can usually cope with these losses. Small children and the elderly are less resilient. If you are ill, you should force fluids - water, broth and bouillon are good choices. However, if you can't keep fluids down because of vomiting or diarrhea over more than eight hours, contact your doctor.

Exercise is important for good health, but it uses fluids very quickly. If you exercise for long periods of time, or if your exercise takes place outdoors in high heat and humidity conditions, you need to replenish fluids early and often. Start drinking extra liquids before you begin your workout. Plan to take regular drink breaks during your exercise period. If you wait until you feel thirsty, you are asking for trouble as thirst is not a reliable indicator of dehydration. Many exercisers choose sports drinks with added electrolytes, but water is actually a fine choice unless you're running a marathon or engaged in some other super-endurance effort.

Excessive heat and sun are environmental factors which cause dehydration. Mild dehydration can quickly become severe when you are in the sun during hot weather. If you'll be at the beach, hiking, boating, swimming or exploring a vacation destination, plan ahead. Bring plenty to drink with you. Find or create some shade to rest in. Wear loose clothing made from natural fibers that allows your skin to breathe and air to circulate. Don't overeat, which can raise your body temperature.

It is also easy to become dehydrated when traveling, but you don't need to let dehydration ruin your vacation.

To prevent dehydration, you should drink liquids frequently throughout the day. Don't wait until you are thirsty! If you plan to exercise, or if you know you'll be in the sun, start drinking extra fluids beforehand. Avoid coffee, tea and other caffeinated beverages because they are diuretics, and cause you to lose extra fluid. Alcohol will also increase, not relieve, dehydration. Bring bottled water with you in the car or on the airplane.

If you find that your mouth feels dry or sticky, you develop a headache, you feel sleepy, dizzy or weak, get out of the sun and force fluids. However, if you are confused or disoriented, irritable, or light-headed, if your heartbeat seems rapid, or if you have not urinated for eight hours, seek medical attention. If your dehydration is severe, you will need to receive fluids intravenously, and you can't do that by yourself at home!

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