Drinking too much water is unlikely to cause liver or kidney problems. However, it can cause other problems. If drunk in too short a period of time, 3-4 L is enough to cause acute hyponatremia, which is tissue swelling triggered by a drop in blood sodium concentration (the brain can fatally swell). Consistently drinking large volumes of water can also cause hypervolemia, fluid overload, which triggers swelling but also high blood pressure and the cardiac risks associated with that.

Unless otherwise medically directed, a typical person should only drink fluids when they feel thirsty, or in a situation where they are being quickly depleted of fluids (intense exercise, hot temperatures, or suffering from diarrhea or vomiting).