In general, there is a time limit for urinalysis, usually not more than 1 hour in summer and 2 hours in winter, after which time a new specimen should be taken. Urine examination mainly includes urine routine, urine culture, urine exfoliative cytology, etc. It is recommended that urine specimens be sent for examination within one hour after collection, especially in summer, when the weather is hot, and if left for too long, it can cause the growth of bacteria in the urine or the decomposition of the components in the urine, resulting in inaccurate test results, false positives or false negatives, affecting the clinical judgment of the disease and delaying the treatment of the disease. Therefore, if the urine examination takes more than one hour in summer and more than two hours in winter, it is recommended to discard and dispose of it. In addition, the first urine test specimen should be taken in the morning as far as possible, and you should not drink a lot of water before taking urine, so as not to dilute the urine and affect the test results.