It is not necessary to fast when testing urine, and it is sufficient to take random urine under normal conditions. In principle, if possible, the first urine in the morning or the urine when the symptoms are most severe, such as the urine when the pain is most severe, the urine when the bleeding is most severe, or the urine when the pain in the small abdomen is most severe, will have a higher chance of a positive result. If it is an ordinary physical examination, normal urination is sufficient without deliberate fasting, and retention of random medication is sufficient. Diet does not have a significant effect on routine urine tests, and random urine can reflect the most common metabolic state of the body, so there is no need to deliberately fast to take urine. Try not to drink as much water as possible between urine retrievals to avoid dilution of the urine. Reduce the intake of foods containing too much sugar in the diet, otherwise it may interfere with the metabolism of sugar in the urine. A normal, ordinary breakfast will not cause abnormal changes in the composition of urine, and random urine can be retained for examination without the need for fasting.