Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

How Much?

We've heard for years that we need to drink eight, 8-ounce glasses of water a day. Before you start chugging, is it true?

"There is no scientific evidence whatsoever for that rule," says Kenney. "It's certainly not a harmful rule, but there is no scientific rationale behind it."

Instead, it's pretty simple: For the average person, drink enough so you go to the bathroom every two to four hours.

"You should be drinking enough so that you urinate every two to four hours, and that the urine is a light color," says Clark, author of Nancy Clark's Sports Nutrition Guidebook. "If you go from 8 a.m. till 3 p.m., and your urine is very dark, that's a sign that you haven't had enough to drink."

Most of us do a pretty good job of getting adequate amounts of fluids as part of our everyday routines: coffee in the morning, soda or juice with lunch, a glass of water in the afternoon, and water with dinner. Coupled with the water that makes up our food, usually, this is sufficient.

Athletes, of course, need more.

"The exact amount of water needed per day really depends on the individual," says Rick Hall, a registered dietitian in Phoenix. "People who exercise, for example, will lose a lot more water through sweat and breathing, so their needs are higher."

Athletes need to quench their thirst even when they're not thirsty, and avoid relying on the feeling of thirst to tell them when to drink.

"Headaches and cramping are common signs of dehydration," says Hall. "However, these are late signs. Unfortunately, the body hides mild dehydration very well, and it can take hours before you recognize that you are dehydrated."

Exercise, explains Hall, blunts the thirst mechanism.

"So folks who are running or biking may not feel thirsty when they actually need water desperately," Hall tells WebMD. "An important strategy is to prevent dehydration by hydrating frequently."

Too Much of a Good Thing

We know we need to drink fluids to maintain a healthy body, but is there such as a thing as too much?

Healthy Recipe Finder

Browse our collection of healthy, delicious recipes, from WebMD and Eating Well magazine.

Top searches: Chicken, Chocolate, Salad, Desserts, Soup

Healthy Recipe Finder