Suddenly drinking more water, there are 2 main diseases that cause this condition: 1. Urogenital disorder, a disease caused by the lack of antidiuretic hormone in the human body. Patients mainly manifest as polyuria, excessive drinking, irritable thirst, the daily volume of urine reaches more than 5000ml, the amount of water drunk is comparable to the volume of urine, and the specific gravity of urine is monitored to be significantly lower. 2, diabetes, patients also manifest as obvious thirst, excessive drinking, polyuria, increased nocturia, and significantly more water drunk than before. The reason for thirst is that elevated urine sugar produces an osmotic diuretic effect, which stimulates the thirst center and causes a significant increase in the amount of water drunk. The easiest way to check the above 2 diseases is to check the urinalysis. If the urine analysis is negative for urine sugar and the urine specific gravity is normal, the above 2 diseases can be excluded.