Normally, your body is made of about 50%-60% fluid, including water, blood, and lymphatic fluid. When your fluid levels are out of balance (too high or too low), serious health problems can happen.

Visit NAP.edu/10766 to get more information about this book, to buy it in print, or to download it as a free PDF. Over the course of a few hours, body water deficits can occur due to reduced intake or ...