The proper number of bathroom breaks seems to be one of the great mysteries of life. Not a day passes without a patient asking Dr. Philippe Zimmern, professor of urology at UT Southwestern Medical Center, ""How much should I drink per day?""

Patients worry about excessive breaks or fear they might damage their kidneys by not drinking enough water. Dr. Zimmern tries to help his patients distinguish myth from reality in regard to the connection between fluid consumption and urination.
 ""Your kidneys filter your blood and produce urine,"" Dr. Zimmern says. ""The more you drink, the more urine your kidneys eliminate because there is no room in your body to store all this fluid. Fluid retention can occur with kidney or heart failure, but generally not otherwise.""
Urine produced is stored temporarily in the bladder. The bladder of the average healthy adult holds around 10 to 15 ounces of fluid. So, how often should a person go to the bathroom?
""The answer is on average six times, depending on fluid intake and bladder capacity,"" Dr. Zimmern says. A person with a smaller bladder volume may have to go up to eight times per day.
To stay within these limits, the average adult should drink no more than six to eight glasses - approximately 64 ounces - of fluids a day, Dr Zimmern says. To avoid having to get up at night to head to the bathroom, simply don't drink after dinner or before bedtime. If you take medications such as a diuretic, do it in the morning or after lunch, Dr. Zimmern advises.
(Source: utsouthwestern.edu)