The Risk of Water Intoxication – Too Much of a Good Thing

March 27th, 2014

Marathon runners can become ill from drinking too much water while running.drink of water while racingImage via Andrew Malone (Flickr)

In my last blog post, I discussed in detail the importance of drinking water. Keeping yourself adequately hydrated is critical to your health, but just as too little water can be deadly, so can too much. It’s important to stay hydrated without going overboard and oversaturating your system with water. Although rare, in some cases, people actually do suffer from water intoxication. The scientific term for this is hyponatremia. Drinking too much water can imbalance your electrolytes just as drinking too little water can, and either way, you can become ill and even die.

Why Too Much Water Is Bad

Hyponatremia means that you do not have a sufficient amount of salt in your system. We constantly hear that too much sodium is a bad thing, and it is, but too little sodium can also be a health risk. Your body needs both water and salt to function properly, and too little or too much of either can cause serious health complications. Normally, your body should have 135 to 145 millimoles of sodium per liter of blood. If that amount is reduced from drinking too much water, you will find yourself fatigued, suffering from nausea and vomiting, frequently urinating, and enduring a headache alongside mental disorientation.

Drinking too much water can also expand your cells. Your kidneys can only flush out so much water per hour, and what it can’t flush out dilutes your blood and makes its way into your body’s cells. You cells begin to expand to accommodate the excess water in your bloodstream, which isn’t as dangerous for your body’s cells as it is for your brain cells. Your muscle and fat cells have room to bloat up with water; your brain cells do not.

You’ve heard of brain swelling, also called edema, in people suffering from high altitude sickness or head trauma. The same concept applies when it comes to water poisoning. When someone ingests significant amounts of water in a short time, the brain cells swell to accommodate the excess fluid, pressing the brain against the skull. The results are frightening, as you might suffer from a variety of conditions, including brain stem herniation, coma, respiratory arrest, seizures, and, yes, death.

How Can You Drink Too Much Water?

Now, I don’t want you reading this and thinking that you need to cut down on your water intake. Chances are good that if you are like many, you actually do not drink enough water per day. It is important to understand that hyponatremia occurs when you drink excessive amounts of water in a short time. For example, instances where people have died of hyponatremia include:

  • People who have used the party drug MDMA – we know it as Ecstasy – and consumed massive quantities of water to relieve dehydration from partying all night
  • Extreme athletes who replenish too much water during workouts, such as marathon runners who sweat out too much salt yet drink too much water while running
  • Infants and small children who are forced to drink more water than their tiny bodies can handle
  • People who are forced to drink gallons of water without urinating, such as during a fraternity hazing or contest
  • People who suffer from a mental illness that causes them to drink water compulsively

As you can see, extenuating circumstances usually lead to hyponatremia, but that doesn’t mean you shouldn’t be conscious about your body’s water balance. So how much is too much? It depends on your overall health, your activity level, and how hot it is outside, among other variables. Generally speaking, however, doctors recommend that you put in what comes out.

How Much Water Should I Drink?

If your kidneys are healthy, and I hope that they are, they will excrete 0.21 to 0.26 gallons of water per hour, so you should be able to drink 0.21 to 0.26 gallons of water without oversaturating yourself. As I said above, outside variables can affect how much water your body is excreting and, therefore, how much you should take in, so you really need to talk with your health care professional to determine your perfect water intake when at rest and when at play.

I also discussed water myths a few blog posts back, and one of those myths is involved with the varying schools of thought surrounding how much water you need every day. Six to eight glasses per day has been debunked by experts, and you shouldn’t drink water until your urine runs clear, either. Adult women need approximately 91 ounces of water per day, and adult men should drink about 125 ounces, per the Institute of Medicine; if your urine is the color of lemonade, you’re adequately hydrated.

If you stick to these simple guidelines and use common sense, you shouldn’t need to worry about water intoxication. Still, the condition is real and deadly, so be wise with your water! Drink plenty of properly filtered water to keep your hydration and electrolytes in balance, and keep in mind that you also get water from certain foods, so include that in your daily tracking. It is also important to keep in mind that as with anything else, too much of anything is bad, even a good thing such as water, so don’t overdo it!


Written By: Lynn Taylor

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