Drinking too much water can lead to a dangerous condition called water intoxication or water poisoning, medically known as hyponatremia. This occurs when excessive water intake dilutes the sodium levels in your blood below 135 mmol/L, disrupting the balance of electrolytes essential for normal cell function

. When sodium levels drop, water moves into your cells to balance the concentration, causing them to swell. While most cells can handle some swelling, brain cells are confined within the skull and cannot expand freely. This swelling increases intracranial pressure, leading to symptoms such as headache, confusion, drowsiness, irritability, and behavioral changes

. If untreated, water intoxication can escalate to severe symptoms including muscle weakness or cramping, double vision, difficulty breathing, seizures, brain damage, coma, and even death due to cerebral edema (brain swelling) and central nervous system dysfunction

. The kidneys can typically process about 0.8 to 1 liter of water per hour. Drinking water faster than this rate over several hours can overwhelm the kidneys, increasing the risk of water intoxication. This risk is higher in endurance athletes, people with certain medical conditions (like kidney or liver disorders), or those taking medications that affect fluid balance

. Treatment depends on severity but may include restricting water intake, administering hypertonic saline to restore sodium balance, using diuretics, and close medical monitoring. Early detection and treatment are crucial to prevent serious complications

. In summary, drinking too much water too quickly can dilute blood sodium, cause cells-especially brain cells-to swell, and lead to potentially life- threatening symptoms. To avoid this, it is recommended to drink water steadily throughout the day rather than consuming large amounts at once