“If you drink enough fluid so that you rarely feel thirsty and produce 1.5 liters (6.3 cups) or more of colorless or slightly yellow urine a day, your fluid intake is probably adequate.”
The issue of too much water surfaces among athletes, especially marathon runners. Hyponatremia is a real concern when replacing the water lost during sweating—too much water, and the salt imbalance in the body can cause cells to swell with water, which is particularly dangerous for brain cells. Hyponatremia symptoms include confusion, nausea and convulsions, according to MedlinePlus. It can also occur in the elderly and hospitalized patients. Some 3.2 to 6.1 million patients get hyponatremia each year, and the condition is associated with congestive heart failure and cancer.