Under normal circumstances, the human body’s urine volume is between 1000-2000ml/day, and the volume of urine is affected by our drinking water, for example, if we drink more water, the volume of urine will increase, and sometimes even more than 2500ml is also normal. If we drink more water and have less urine, it is usually abnormal. Common causes: First, the patient himself is in a state of dehydration, eating less or in a state of dehydration, such as heatstroke, gastrointestinal bleeding or hepatorenal syndrome, leading to dehydration. Second, the patient may have some renal function damage problems, such as the patient has acute renal failure, chronic renal insufficiency and other conditions. Third, there may be urinary tract obstruction, such as patients with ureteral stones, and the resulting urine can not be discharged, so for the case of drinking a lot of water, urine instead of less should be timely to the hospital, to clarify the cause of the disease.