How Much Water Is Too Much? The Hidden Dangers of Overhydration

Drinking 2–3 liters of water per day is a common recommendation, but is it okay to drink more than that? While proper hydration is essential for health, excessive water consumption can be dangerous and even fatal in some cases.

Drinking water is one of the most important habits for maintaining good health. While guidelines such as “drink eight glasses a day” or “2–3 liters daily” are widely known, it's important to understand the limits and effects of overhydration.

A review published in JAMA Network Open found that adequate water intake is linked to weight loss, prevention of kidney stones, improvements in conditions such as migraines and urinary tract infections, as well as diabetes management. However, excessive water intake can lead to a dangerous medical condition known as hyponatremia, which is an imbalance in blood sodium levels.

The human body is composed mostly of water: the brain and kidneys contain between 75%–80% water, while bones hold only about 20%–25%. While water supports the healthy function of organs, too much can cause severe problems. Hyponatremia occurs when overhydration dilutes the salt concentration in the blood. This condition is especially dangerous for athletes who drink large amounts of water without replenishing lost salts through sweat, infants fed diluted formula, and adults taking diuretic medications.

Symptoms of water intoxication include headaches, nausea, fatigue, frequent urination, and altered mental status. In severe cases, it can lead to brain damage or even death.

Adults should aim to stay properly hydrated, especially since aging reduces the body's ability to regulate temperature, and dehydration can cause fatigue and muscle pain. However, overhydration is equally risky. Maintaining balance is therefore crucial, and consulting health professionals in cases of uncertainty is highly recommended.