You hear the "rules" thrown around all the time: Drink eight glasses of water a day. Drink half your body weight in water a day. If you're already thirsty, it's too late, you're dehydrated.
And while you certainly know it's not pleasant to feel parched, staying hydrated is important for a host of other reasons. Water aids digestion, flushes out toxins, lubricates the joints and keeps your memory sharp. When you're dehydrated, your eyes, nose, mouth, skin and hair will also feel dry.
The Institue of Medicine (IOM) established some general guidelines for water intake in 2004. Healthy adult women need around 91 ounces of total water and healthy adult men need about 125 ounces every day.
But that doesn’t mean you need to chug over 11 cups of water every day. "Total" water also includes the water in other beverages -- yep, even that coffee -- as well as the water in hydrating, high-water-volume foods. About 80 percent of our daily water intake comes from beverages, and the remaining 20 percent comes from the foods we eat.
There are some situations in which you'll want to throw a few extra ounces back: Hot, humid weather causes us to lose more water from sweat, and if you're sick with a fever or vomiting you'll be losing extra liquids too. Women who are pregnant or breastfeeding also require extra water, as do athletes or exercisers who lose extra water from sweat, according to Mayo Clinic.
It's true that thirst is a symptom of dehydration, so try to remember to sip fluids throughout the day. But don't overdo it: It is possible to drink too much water, which, frighteningly, can kill you.
One way to keep on top of your hydration is to keep an eye on the color of your urine. Lawrence Armstrong, Ph.D., an exercise physiologist and professor at the University of Connecticut's Human Performance Laboratory, established a urine color chart to accurately depict levels of dehydration. While Armstrong does not allow online reproduction of the chart, as the colors may appear differently on different computer monitors, color printers and web sites, numerous other outlets, including the U.S. Navy and Marine Corps, the New York Times and the Boy Scouts of America have since created their own digital versions of the color chart.
The slideshow below is based on the colors presented by the Boy Scouts of America. The goal is to produce urine the color of lemonade, ideally in the range of colors one through three. If your urine is in the range of colors four through eight, you need to drink more fluids and may need to consult your doctor. (Note: This slideshow is not for clinical use, but can be used as a basic guideline.)
Keep in mind that other things can temporarily change the color of your urine, including some medications, beets, blackberries and artificial coloring in foods, according to MedlinePlus. Vitamins and supplements are also likely to have an affect, often producing urine that is bright yellow, mimicking the colors indicative of dehydration in the slideshow below.
For more on diet and nutrition, click here.
Flickr photo by Dave Johnston