Urine is getting less and less, it is recommended to go to the hospital for examination to clarify the presence of disease. Under normal circumstances, the daily urine output is greater than 400mL or more, it is not considered a small amount of state. If the urine volume is less than 400mL, the possible reasons: 1, renal failure, renal failure caused by various reasons, such as nephritis or post renal obstruction, hydronephrosis, etc. can cause a decrease in urine volume, because of the decline in the filtration capacity of the kidneys, the water in the body can not be filtered through the kidneys to be discharged out of the body, the metabolic wastes accumulate in the body, resulting in a decrease in the volume of urine, which can be accompanied by edema or nausea, vomiting, Dizziness, etc., need to carry out renal function tests to further clarify the existence of renal failure. 2, post-renal obstruction, often seen in ureteral obstruction, ureteral stenosis or male prostatic hyperplasia, urethral stenosis, etc., is often the kidney produces normal urine, but the process of discharging it is obstructed. Ureteral stenosis results in urine not being completely eliminated and accumulation in the kidneys can result in decreased urination. In men with prostate enlargement, the urine produced by the kidneys accumulates in the bladder and cannot be excreted smoothly will result in a reduced urine output.