The causes of excessive urination after drinking water are categorized into physiological and pathological causes, such as decreased secretion of antidiuretic hormone, cystitis, tuberculosis, and so on. 1. Physiological reasons: After drinking water, antidiuretic hormone secretion decreases, water reabsorption decreases, leading to the phenomenon of excessive urination, which is a normal physiological phenomenon. Pregnant women can be due to the pressure of the fetus on the bladder, resulting in a reduction in the capacity of the bladder, the bladder is unable to store too much urine after drinking water, resulting in more urine after drinking water is also normal. 2. Pathologic causes: (1) cystitis: it can be caused by inflammatory stimulation leading to the phenomenon of excessive urination after drinking water, which may also be accompanied by urinary pain, hematuria and other symptoms. (2) bladder tuberculosis: bladder tuberculosis patients can lead to contracture of the bladder, bladder capacity decreased, resulting in excessive urination after drinking water. There are many other causes of excessive urination after drinking water, so it is recommended that such patients go to regular hospitals, consult professional doctors, cooperate with doctors to improve the examination, and actively deal with it.