YOUR BODY FEELS GREAT WHEN YOU HYDRATE  
by 
Lawrence Ross, M.D.
When you’re dehydrated, your body signals its lack of water in numerous ways. One of the best gauges for recognizing dehydration is by noting the color of your urine. 

Water excreted from the body that is pale yellow and with little odor is usually a good indicator that you are properly hydrated. A darker yellow color means you're not drinking enough water. 

How do you become dehydrated? Just by breathing you lose a pint or more of water a day. You can lose a quart of water in sweat after only one hour of exercise while about 1.5 quarts of water a day is lost during urination (at a rate from 6-60 ml/hr). 

As you might expect, most of the fluids we lose each day go through the kidneys. Kidneys act like giant filters, filtering our blood twenty times every hour. Since human blood is 95% water, much of the function of the kidneys has to do with the filtering and disposal of water. A constant flow of water keeps the kidneys operating at peak efficiency. In addition, consumption of 8-10 glasses a day has been proven effective in reducing incidences of urinary tract infections in women. Stimulating increased excretion of water flushes out bacteria that can lead to infection.

  
"You should be drinking about one half-ounce of water for each pound of body weight each day." 
 

You should be drinking about one-half ounce of water for each pound of body weight each day to stay properly hydrated -- two-thirds of an ounce per pound if you are very active. It’s important that water is consumed instead of fluids with caffeine and alcohol, which act as diuretics and cause the body to lose water. 

Sugary juices aren’t any better. In fact, according to the September, 1997 issue of Men’s Health magazine, drinking apple juice or grapefruit juice instead of water can increase your risk of kidney stone formation by 36 percent. 

Considering that a 165 pound adult is composed of 50 quarts of water, it’s important that the body’s water levels are maintained. It makes you feel good and keeps your body healthy. 

Lawrence S. Ross, M.D. is a Chicago-based urologist and Head of the Department of Urology at the University of Illinois College of Medicine and Chief of Service at the University of Illinois Hospital and Humana Hospital/Michael Reese, Chicago.