If the urine routine is normal, but there is frequent urination, then the possible causes are: 1. Physiological excessive drinking. At this time, no infection has occurred, but only because the blood volume has increased after drinking too much water, at which time the amount of filtered blood in the kidneys also increases, and more urine is produced. Patients will then experience frequent urination and increased urine volume. It is recommended to reduce water consumption appropriately and observe whether the frequency of urination has improved. 2. Decline in bladder function, such as a decrease in bladder capacity, can lead to bladder contracture after various diseases, such as having suffered from bladder tuberculosis, bladder trauma, after surgical removal, and when there has been a long-term chronic urinary tract infection in the past, the effective bladder capacity decreases. However, at this time, all urine examination is normal and no infection has occurred. Because of the reduced bladder capacity, urine stored in the bladder produces more frequent urination than normal. In this case, it is necessary to exercise the bladder function and take oral medication to reduce the bladder contracture.