Who would ever imagine that water could be controversial? Yet discussions of how much water you should drink every day-or even what type of water is best-can get quite contentious. Becoming dehydrated is dangerous, of course, but should you worry that you might over hydrate?
Can You Over Hydrate by Drinking Too Much?
Q. Is it possible to over hydrate? When I was growing up, no one carried a bottle of water around. Now it seems as if everyone is constantly sipping bottled water throughout the day.
One friend believes that if she doesn’t drink at least 8 to 10 glasses of water daily she is jeopardizing her health. Couldn’t consuming too much water lead to dangerously low sodium levels by dilution?
A. People used to drink when they were thirsty, but these days there is a widespread belief that the more water we drink the healthier we will be. Unless someone has had a kidney stone, there is no evidence that extra fluid consumption throughout the day is beneficial. If the kidneys are working properly, medical guidelines suggest that thirst is a good indicator for when you need to drink. One exception: the elderly, whose kidneys and thirst mechanisms may not be in sync, might need to pay attention to getting adequate fluids.
People who are sweating heavily, such as marathon runners in hot weather, may be thirsty enough to drink a lot of water. They need to be careful to replace electrolytes as well, since over hydration with plain water can lead to sodium depletion (hyponatremia). This can be life threatening.
Sometimes people are told that beverages such as coffee, tea or juice “don’t count” and that they need to drink water above and beyond their intake of other beverages. We are assured that all the liquids you drink and even those included in foods get used by the body to satisfy its fluid requirements. As a result, most people during a normal day don’t really need to force themselves to drink more water.