Dear Dr. SerVaas: We're always told to drink at least eight 8-ounce glasses of water a day. I take a diuretic (water pill) to help control hypertension. How much water should people drink if they're on a diuretic?

Cornelia VanZee
Newark, New Jersey

Dear Reader: Indiana University hypertension expert Dr. Myron Weinberger provides the following surprising comments:

"There is no scientific evidence to support the recommendation to drink eight 8-ounce glasses of water a day. In some circumstances, consuming that much water could be harmful.

"Diuretics are given to remove the excess salt and water from the body. Therefore, consuming an increased amount of water could interfere with the effectiveness of the diuretic, depending on the reason for which it was prescribed.

The current recommendation is for healthy people to consume fluid when they are thirsty."