Water poisoning is a symptom of dehydration and hyponatremia caused by excessive intake of water. Although the probability of death from water poisoning is very low, it is still possible. The maximum sustained diuresis rate of human kidney is 16 ml per minute. Once the water inflow rate exceeds this standard, the excess water will expand the cells, thus causing dehydration and hyponatremia. When drinking too much water, the electrolyte in the blood drops to a concentration lower than safe water because it is excreted by water, which affects the operation of the brain and may be fatal.