Asking, “Can you drink too much water?” might sound like a dumb question, considering every cell and organ in your body requires a steady stream of the stuff to function properly (the bottled water industry constantly reminds us of this). But the truth is, you certainly can drink too much water—and doing so could even be the death of you.
What Happens If You Drink Too Much Water
Hyponatremia, aka water poisoning or water intoxication, is a condition that occurs when the sodium levels in our body fluids drop due to excess water consumption. This causes our cells to swell (particularly those in the brain), which in severe cases, can result in seizures, brain damage, coma and even death. Even scarier is the fact that hyponatremia is much more common than most people realize: A study published in 2005 in the New England Journal of Medicine suggests nearly one in six participants in 2002’s Boston Marathon experienced some degree of hyponatremia.
While death is reserved for only the most severe cases of water poisoning, it does happen: A 2002 report describes how three U.S. soldiers (one of whom was going through basic training) died due to hyponatremia and cerebral edema (that’s when excess fluid accumulates in the brain, causing a central nervous system dysfunction). Note, however, that these soldiers drank a ton of water in an extremely short period of time: The deaths were associated with drinking 2.5 to 5.6 gallons of water in just a few hours.
Nutritionist Carolyn Dean points out that hypothermia isn’t the only negative side affect of drinking too much water: “Clear urine may mean you’re drinking too much water, and therefore, you’re losing essential minerals like magnesium — lighter shades of yellow (rather than totally clear) tend to show that you’re properly hydrated,” she explains, adding that a magnesium deficiency can cause everything from irritability and anxiety to seizures and coronary spasms.
So, once and for all, can you drink too much water? Heck to the heck yes.
How Much Water Is Too Much Water?
According to a 2013 study, symptoms of hyponatremia can occur after drinking just one gallon of water within a few hours. A more specific way to understand how much water is too much water is to look at how much fluid your kidneys can process: A 2007 panel explained that the kidneys are capable of excreting up to seven gallons of fluid per day. However, they can’t excrete more than around 0.25 gallons per hour (that’s four eight-ounce glasses of water)—therefore, drinking any more water than that can lead to minor hyponatremia symptoms, like confusion, nausea and vomiting. (Again, the soldiers who died from hyponatremia drank a whopping 2.5 to 5.6 gallons of water—that’s 40 eight-ounce glasses of water on the low end and nearly 90 eight-ounce glasses of water on the high end—in just a few hours, so it takes a lot to actually drink yourself to death).
How Much Water Is Just Right?
As we learned in a previous article debunking the myth that we need to drink eight glasses of water per day, how much water you actually need to drink depends on a couple of things:
How much water you need to drink also depends on how much hydration you get from other sources, like water-rich foods or non-water beverages (while soda, for instance, does count toward your daily water intake, it also contains additives like sodium and caffeine that can potentially dehydrate you if you’re sensitive to caffeine). Sharad Paul, author of The Genetics of Health, puts it simply: “The best guide for staying hydrated is drinking water when your body asks for it.” Recent research found that it becomes more difficult to swallow water when you’re already hydrated, so more specifically, listen to your throat.
In other words, it’s a matter of common sense.
To sum up what happens if you drink too much water: Your cells expand, which will lead you to feel like crud. Then if you continue drinking, you might just drink yourself to death—all of which leads us to believe that, “Can you drink too much water?” actually isn’t such a stupid question after all.