Why Drinking Too Much Water Is Dangerous

Why Drinking Too Much Water Is Dangerous

By Dr. Ben Kim on March 04, 2007

On January 12, 2007, a 28-year old Californian wife and mother of three children died from drinking too much water. Her body was found in her home shortly after she took part in a water-drinking contest that was sponsored by a local radio show. Entitled "Hold Your Wee For A Wii," the contest promoters promised a free Wii video game machine to the contestant who drank the most water without urinating.

It is estimated that the woman who died drank approximately 2 gallons of water during the contest. When she and other contestants complained of discomfort and showed visible signs of distress, they were laughed at by the promoters and even heckled.

This tragic news story highlights the importance of understanding why drinking too much water can be dangerous to your health.

Whenever you disregard your sense of thirst and strive to ingest several glasses of water a day just because you have been told that doing so is good for your health, you actually put unnecessary strain on your body in two major ways:

Ingesting more water than you need can increase your total blood volume. And since your blood volume exists within a closed system - your blood circulatory system - needlessly increasing your blood volume on a regular basis puts unnecessary burden on your heart and blood vessels.

Your kidneys must work overtime to filter excess water out of your blood circulatory system. Your kidneys are not the equivalent of a pair of plumbing pipes whereby the more water you flush through your kidneys, the cleaner they become; rather, the filtration system that exists in your kidneys is composed in part by a series of specialized capillary beds called glomeruli. Your glomeruli can get damaged by unnecessary wear and tear over time, and drowning your system with large amounts of water is one of many potential causes of said damage.

Putting unnecessary burden on your cardiovascular system and your kidneys by ingesting unnecessary water is a subtle process. For the average person, it is virtually impossible to know that this burden exists, as there are usually no obvious symptoms on a moment-to-moment basis. But make no mistake about it: this burden is real and can hurt your health over the long term.

Forcing your body to accept a large amount of water within a short period of time - say, an hour or two - as several contestants did during the "Hold Your Wee for a Wii" contest can be fatally dangerous to your health. Here's why:

If you force large amounts of water into your system over a short period of time, your kidneys will struggle to eliminate enough water from your system to keep the overall amount at a safe level.

As your blood circulatory system becomes diluted with excess water, the concentration of electrolytes in your blood will drop relative to the concentration of electrolytes in your cells. In an effort to maintain an equal balance of electrolytes between your blood and your cells, water will seep into your cells from your blood, causing your cells to swell.

If this swelling occurs in your brain, the bones that make up your skull hardly budge. The result is an increase in intracranial pressure i.e. your brain gets squeezed. Depending on how much water your drink in a short period of time, you could experience a wide variety of symptoms, ranging from a mild headache to impaired breathing. And as occurred recently in the tragic water-drinking contest, it is quite possible to die if you drink enough water in a short enough period of time.

This information is particularly important for parents to pass on to their children. Foolish water-drinking contests are not uncommon among high school and university students, especially while playing cards.

So how much water should you drink to best support your health?

The answer to this question depends on your unique circumstances, including your diet, exercise habits, and environment.

If you eat plenty of foods that are naturally rich in water, such as vegetables, fruits, and cooked legumes and whole grains, you may not need to drink very much water at all. If you do not use much or any salt and other seasonings, your need for drinking water goes down even further.

Conversely, if you do not eat a lot of plant foods and/or you add substantial salt and spices to your meals, you may need to drink several glasses of water every day.

Regardless of what your diet looks like, if you sweat on a regular basis because of exercise or a warm climate, you will need to supply your body with more water (through food and/or liquids) than someone who does not sweat regularly.

Ultimately, the best guidance I can provide on this issue is to follow your sense of thirst. Some people believe that thirst is not a reliable indicator of how much water you need, since many people suffer with symptoms related to dehydration and don't seem to feel a need to drink water on a regular basis. My experience has been that most people who are chronically dehydrated have learned to ignore a parched mouth. If you ask such people if they are thirsty and would like a piece of fruit or a glass of water, they will almost always realize that they are indeed thirsty.

Some people suggest observing the color of your urine as a way of looking out for dehydration. The idea is that clear urine indicates that you are well hydrated, while yellow urine indicates that you need more water in your system. While this advice is somewhat useful, it is important to remember that some chemicals (like synthetic vitamins) and heavily pigmented foods (like red beets) can add substantial color to your urine. Thumbs down for synthetic vitamins, and thumbs up for red beets and other richly colored vegetables and fruits.

The main idea that I wish to share through this article is to beware of mindlessly drinking several glasses of water per day without considering your diet, exercise habits, climate, and sense of thirst. And when you do find yourself in need of water, remember that you can get it from liquids and/or whole foods.