Half of the people who have had a kidney stone will develop another one. A key way to reduce the risk of forming stones is to drink extra water. This dilutes the substances in urine that lead to stones. To prevent repeat stones, try to drink at least 3 quarts (about ten 10-ounce glasses) of liquid a day.
The amount of liquid you need to drink depends on the weather and your activity level. If you live, work, or exercise in hot weather, you may need more liquid to replace the fluid you lose through sweat.