Possible reasons for frequent urination alone: 1, reduced bladder capacity, when the patient has bladder contracture or a history of partial bladder removal surgery, resulting in a small effective bladder capacity, less urine stored in the bladder, will only appear frequent urination, but not accompanied by any other conscious symptoms. 2, there may be irritating factors in the urinary tract, such as stones and polyps in the urinary tract, when the stones and polyps are small in size and do not The stones and polyps are small and do not cause other symptoms, but they can cause frequent urination. This is the early lesion of stones and polyps. 3. Overactive bladder syndrome, because the bladder forced urinary muscle contracted too often, the patient only showed frequent urination, not accompanied by any pain, incomplete urination, etc. At this time, urine routine examination, urinary system ultrasound examination are normal, which is a functional disease. 4. Psychological frequency of urination, such as excessive tension and fear, can cause a decrease in the secretion of antidiuretic hormone, which can lead to an increase in the volume of urine and frequency of urination.