Drinking too much water can lead to a condition called water intoxication or hyponatremia, where excess water dilutes the sodium in your blood, causing cells—including brain cells—to swell. This can result in symptoms ranging from headache, nausea, fatigue, confusion, and muscle cramps to more severe effects like seizures, loss of consciousness, brain damage, or even death in rare cases
. How much water is too much?
- The kidneys can typically process about 1 liter (approximately 32 ounces) of fluid per hour. Consuming more than this amount over several hours can be risky and potentially cause overhydration
- Drinking more than 3.5 to 4 cups (about 0.8 to 1 liter) of water in an hour may lead to overhydration
- Symptoms of water intoxication often begin after consuming 3 to 4 liters of water in a few hours
- Endurance athletes and people with certain medical conditions or on specific medications are at higher risk of overhydration
General hydration advice:
- There is no one-size-fits-all daily water intake; it varies by individual factors such as age, activity level, and health.
- The National Academy of Medicine suggests about 15 cups (3.7 liters) of fluids daily for men and 11 cups (2.7 liters) for women, including fluids from food
- A practical approach is to drink according to thirst and monitor urine color: light yellow indicates good hydration, while dark yellow suggests dehydration; overly clear urine combined with excessive water intake may indicate overhydration
In summary, drinking water steadily throughout the day and not exceeding about 1 liter per hour is key to avoiding water intoxication. Rapidly consuming large volumes of water, especially beyond 3 to 4 liters in a few hours, can be too much and dangerous
