It is not mandatory to have the first urine in the morning to perform a laboratory test of urine, but the first urine in the morning, because of the higher solute concentration component in the urine, may have a higher possibility of finding positive disease in the process of doing the test. Urine from other times, such as after drinking a lot of water, or using some food, may have abnormal items, such as diluted urine or abnormal urine sugar content, resulting in inaccurate test results. However, it is not required that it must be the first urine in the morning. If the urine is taken at the time when the symptoms of the disease are most serious, the test results are also more accurate at this time, such as urine-related examination when bleeding in patients with hematuria, which is a more accurate test result, and if the urine is taken at the time when the pain in the urinary system is most serious, it can also indicate the existence of relevant lesions in the urinary system and help further judgment. So it is not required that it must be the first urine in the morning, but in principle, the first urine is retained as much as possible, and the accuracy of the examination is relatively high at this time.