The amount of water a person can safely drink varies, but generally:
- For daily hydration, men are recommended to consume about 15.5 cups (3.7 liters) of fluids and women about 11.5 cups (2.7 liters), including all beverages and water in food
- The kidneys can process roughly 0.7 to 1 liter of water per hour. Drinking more than this in a short period can overwhelm the kidneys and lead to water intoxication, a dangerous condition caused by diluting blood sodium levels (hyponatremia)
- Symptoms of water intoxication can start after consuming more than 3 to 4 liters of water within a few hours and include headache, muscle cramps, nausea, confusion, and in severe cases, seizures, brain swelling, coma, or death
- Drinking extremely large amounts, such as 8 to 10 liters per day, especially rapidly, can cause serious health problems and even be fatal, though this is rare and usually linked to intense physical activity or certain medical conditions
In summary, while daily water needs vary, exceeding about 1 liter per hour consistently is risky. A good practice is to drink according to thirst and consider factors like exercise, temperature, and health status to avoid both dehydration and overhydration
