Water is essential for all body cells to function, and dehydration can severely impact health. While the body can regulate itself with mild excess water, provided it is not consumed too quickly, ingesting too much water in a short period can easily disrupt electrolyte balance, especially sodium levels in the blood.

Excessive water intake can lead to water intoxication, causing brain dysfunction. This occurs when water accumulates in cells, including brain cells, causing them to swell and increasing intracranial pressure, known as cerebral edema. Symptoms may include headache and drowsiness; in severe cases, it can lead to increased blood pressure and a slow heart rate.

When the body has excess water, sodium is the most affected electrolyte, leading to hyponatremia. Reduced sodium levels cause more water to enter cells, increasing the risk of seizures and coma.

Warning signs of excessive water intake include frequent urination, clear urine, a feeling of fullness, or nausea. This happens because the body cannot excrete the excess water quickly enough, forcing cells to retain more water and swell to adapt.

General recommendations suggest that healthy adults should consume approximately 2 liters of water daily, equivalent to about 8 cups. This intake includes plain water, other beverages, and water-rich foods, but it should be adjusted based on living environment, activity level, and overall health status.

It is advisable to drink water slowly and spread intake evenly throughout the day, rather than consuming it rapidly. Sipping small amounts helps the body absorb water more effectively and reduces the burden on the kidneys in processing excess fluid.

Associate Professor, Doctor Nguyen Trong Hung

National Institute of Nutrition