How Much Water Does the Human Body Need Daily?

by Jan Sheehan, Demand Media
    Most women should drink about 9 cups of water a day.

    Most women should drink about 9 cups of water a day.

    Water is essential for life. You lose water when you sweat, go to the bathroom and even when you breathe, so you must constantly replace it. If you don’t drink enough water, you’ll become dehydrated, which could have serious health consequences. How much water the human body needs depends on a number of factors.

    Water Needs

    Most women need about 9 cups of water a day, while men should drink about 13 cups. During hot, humid weather, you may need to drink more to replace the fluids that you lose in sweat. For the same reason, exercise increases your water needs. MayoClinic.com recommends drinking at least an extra 1 1/2 cups of water if you’re exercising moderately. A woman’s water needs also increase while she’s pregnant and nursing. Shoot for about 10 cups of water a day while you’re pregnant and 13 cups a day during the months you’re breast-feeding, recommends Hilda Hutcherson, M.D., clinical professor of gynecology and obstetrics at Columbia University. Your blood volume increases significantly while you’re pregnant, which requires more water, and breast milk is largely composed of water.

    Water Benefits

    Water flushes toxins from your body, carries nutrients to your cells and keeps the tissues of your nose, throat and ears moist, MayoClinic.com reports. Water also gives you energy by preventing dehydration. Drinking eight to 10 glasses of water a day may also aid in weight loss and prevent bloating. When you don’t stay hydrated, your kidneys compensate by retaining water, leading to unwanted water weight, according to the University of Maryland Medical Center. Plus, drinking plenty of water makes your stomach feel fuller, reducing hunger and preventing overeating. In a 2008 study of overweight women in Oakland, California, drinking more water resulted in significant weight loss.

    Dehydration Signs

    If your urine appears dark yellow rather than clear or pale yellow, you may be dehydrated, cautions MayoClinic.com. Other signs of dehydration include thirst, a dry, sticky mouth, dry skin, lack of energy, a headache and constipation. Rehydrating with water will usually reverse mild to moderate dehydration. Severe dehydration is more serious. Signs include extreme thirst, lack of sweating, little or no urination, low blood pressure, rapid breathing, a fast pulse, dizziness and confusion. Severe dehydration requires immediate medical attention. It can be life threatening.

    Considerations

    In addition to drinking water, you can meet your water needs by eating foods containing high amounts of water. On average, food provides 20 percent of your total water intake, according to MayoClinic.com. Fruits and vegetables with high amounts of water include watermelons and tomatoes. Soup broths can also be hydrating. Milk and juice can help keep you hydrated, but caffeinated and alcoholic beverages can be dehydrating. MayoClinic.com says that drinking water is the best way to stay hydrated because it’s calorie-free, inexpensive and available everywhere.

    About the Author

    Jan Sheehan is an award-winning medical and nutrition writer, having entered journalism in 1992. She is a former contributing editor for "Parents" magazine. She has also written nutrition articles for "Self," "Fitness," "Ladies' Home Journal," "Health" and other magazines. Sheehan has a Bachelor of Arts in journalism from Purdue University.

    Photo Credits

    • Creatas Images/Creatas/Getty Images