Yes, it is possible to drink too much water, which can lead to a condition called water intoxication or overhydration. Drinking too much water in a short period can overwhelm the kidneys, which can only process about 0.8 to 1.0 liters of water per hour. When excessive water dilutes the sodium in the blood, it causes a dangerous imbalance known as hyponatremia. This leads to water entering cells and causing them to swell, which is especially dangerous in brain cells because it increases pressure inside the skull and can cause symptoms ranging from mild to severe. Symptoms of water intoxication include headache, nausea, vomiting, fatigue, confusion, muscle cramps, drowsiness, double vision, difficulty breathing, seizures, and in extreme cases, coma or death. Overhydration is rare and usually occurs in specific situations such as intense exercise or mental health conditions.

In general, drinking according to thirst and maintaining pale yellow urine helps avoid overhydration. The recommended daily water intake varies per individual but generally is around 9 cups for women and 13 cups for men, including fluids from all sources.

Thus, while water is essential for health, it is possible and potentially dangerous to drink too much, especially quickly and in large quantities.