Clinical examination of the urine test is not recommended to drink a lot of water, because a short period of time after drinking a lot of water will increase the urine volume, urine volume increases lead to dilution of urine, corresponding to the urine of white blood cells, protein, red blood cells and other corresponding proportional reduction, thus affecting the clinician on the patient’s condition of the determination of the severity of the disease. If it is not an emergency examination, it is recommended to take the best morning fasting urine specimen. If the usual random clinic, you can take the urine specimen that stays in the body for more than 2 hours. If the patient is an emergency can be randomly collected urine specimen, if necessary, can be reviewed as soon as possible urine specimen, in order to guide the clinical treatment.