Which organ is damaged by too much water?

What Happens When You Drink Too Much Water?

Most of us know that staying hydrated is essential for good health. But did you know it’s possible to drink too much water? While rare, overhydration can be dangerous—and it’s your kidneys that bear the brunt of the damage.

When you consume more water than your body can process, your kidneys struggle to filter the excess. This overwhelms their capacity and leads to a serious condition known as water intoxication, or hyponatremia. Hyponatremia occurs when the sodium levels in your blood become dangerously diluted. Sodium is crucial for maintaining fluid balance, nerve function, and muscle performance. When it drops too low, cells begin to swell—including brain cells—which can lead to headaches, confusion, seizures, and in severe cases, coma or even death.

This kind of overhydration is uncommon in healthy adults with regular diets and lifestyles. However, it’s more likely to happen during intense physical activity—like marathon running—when people drink large amounts of water without replacing lost electrolytes. Endurance athletes are particularly at risk, especially in hot conditions.

Your kidneys are remarkably efficient, processing about half a liter to one liter of water per hour. Pushing beyond that limit in a short time can exceed their capacity. The key isn’t to drink less water overall, but to listen to your body. Thirst is a reliable guide for most people. In longer, more strenuous activities, consider electrolyte-rich drinks to maintain balance.

So while water is life, even the best things come with limits. Respect your body’s signals, and let your kidneys do their job without being overwhelmed.