Why does hydration matter? Fluid balance, the state in which fluid intake equals output, is essential to health, regardless of a person’s age. In older adults, adequate fluid consumption has been associated with fewer falls, lower rates of constipation, and lower rates of laxative use, as well as better rehabilitation outcomes in orthopedic patients and reduced risk of bladder cancer in men. Drinking five or more 8-oz. glasses of water (but not other liquids) per day has been associated with lower rates of fatal coronary heart disease in middle-aged and older adults than drinking two or fewer glasses And in one study, drinking 16 oz. of room temperature water before a meal resulted in signifi- cantly lower rates of postprandial orthostatic hypotension in older adults who had autonomic failure.