By Felipe Fernandez del Castillo, MD
Division of Nephrology

It’s true, in certain instances overhydration (also known as water intoxication) can be a real health danger. In fact, there are documented cases of people dying simply from drinking too much water.

Fortunately, overhydration leading to death is quite rare. It can happen, for example, when endurance athletes, football players and members of the military consume much more water than necessary because they are worried about getting dehydrated during an athletic event or training exercise.

Much more commonly, mildly excessive hydration (often referred to as hyponatremia or low sodium) can lead to confusion, gait instability, and hospitalization. While most people can drink up to 3 or 4 gallons of fluid per day without developing consequences (other than spending the day running to the bathroom), the elderly, people with low protein intake, and patients taking certain medications often have an impaired ability to excrete excess water from their kidneys and are at higher risk of developing symptoms. This is a problem that I see several times a week when I round in the hospital.

Quite simply, chugging water or any other beverage is not a good idea. So, how do you prevent problems from dehydration or overhydration? The answer is pretty simple – drink when you are thirsty. Our bodies do a great job of signaling us when we need to drink by making us thirsty. So, always listen to what your body is telling you. Most experts agree that unless directed by a doctor or another caregiver, there is no set amount of water you need to drink each day. (That’s right, there is no real scientific evidence supporting the idea that everyone should drink eight glasses of water per day).

If you are experiencing excessive thirst and drinking a lot of water, be sure to talk to your doctor as this may indicate a serious medical condition.