Water & Your Health: Can Drinking Too Much Water Harm Your Health?

Wednesday, October 25, 2006 - 10:49am

By Rose Giordano

We’ve all seen people toting water bottles around town, in the mall, and at work. Some of them carry plastic, store-bought bottles, while others have more fashionable color coordinated screw-top containers. And who hasn’t overheard a really health conscious person brag about how she drinks at least a gallon of water per day? What does this say? Most people know that water is a very important part of our diet.

How important is water for your body?

A lot of people don’t realize that water is our body’s most essential nutrient. Why? Because our body cannot make it in sufficient quantities to satisfy the needs of our metabolisms. You see, water is required for almost all nutrients to work properly. One of water’s many important functions is to enable our bodies to regulate our internal temperatures during exercise and when we are in warmer climates. Another important function is to help our bodies optimize the balance of our fluids.

Can water harm your body?

There have been plenty of discussions about the negative effects of not drinking enough water. Dehydration can cause decreased endurance during exercise, decreased mental functioning, as well as a variety of other symptoms. However, there is another adverse water-related condition, which is actually the opposite of dehydration: hyperhydration or “water intoxication.” Hyperhydration occurs when you drink excessive amounts of water.

What happens during hyperhydration?

When you “hyperhydrate,” you can get a condition called hyponatremia. With hyponatremia, water dilutes the sodium in your bloodstream. This condition can be very dangerous because sodium plays a major role in the fluid balance of cells. Symptoms of hyponatermia may be mild and can include bloating, nausea, headaches, and vomiting. More severe symptoms can include coma, brain swelling, respiratory arrest, and death.


How much water should you drink?

That’s not an easy question to answer. No one has exactly the same hydration needs. The old adage of drinking eight 8-ounce glasses is one way to approach your daily requirement. However, use this rule as a guideline because there isn’t much scientific evidence to support it. Another approach is to balance your water intake with how much you lose. For example, the average person’s urine volume is approximately 1.5 liters per day. Add to that amount a second liter, which is used up by metabolism to perform basic functions such as breathing and sweating.

In certain situations it is OK to hyperhydrate, such as prior to participating in sports activities or in warmer temperatures when your excessive sweating will balance out your increased intake.

Overall, most people drink enough water to suit their needs and should not worry about how much water they are drinking everyday.

Because sodium is excreted when you sweat, so you can also get hyponatremia after sweating excessively. Notably, in athletes the most common cause of hyponatremia is excessive fluid intake.

Source: Nutrition for Health, Fitness and Sport. Williams, MH 2005