There is no urine but seems to be urgent, the possible causes: 1, acute infection of the urinary tract, such as acute cystitis, urethritis can produce the above symptoms, because the bladder urethral mucosa due to inflammation of acute congestion, edema, sensitivity, storage of a small amount of urine can produce a strong sense of irritation, accompanied by urinary urgency, urinary incontinence, and so on. However, at this time because the urine volume is too small, so can not discharge the urine, need to carry out urine related examination to further confirm the diagnosis. 2, overactive bladder, the bladder storage of urine is not much, but because of the bladder forced urinary muscle frequent over-contraction, so produce a strong willingness to urinate, not much urine performance, usually not accompanied by urinary pain,, urine abnormalities, cloudy or urine sedimentation, etc.. Routine urine laboratory tests and urine culture tests are normal, need to further urodynamic examination to confirm the diagnosis. 3, the presence of stones, tumors and other irritating factors in the urinary tract and lead to frequent urination, but the urine volume is not much of the case, may be accompanied by urination pain, hematuria, etc., need to carry out ultrasound examination of the urinary system to further confirm the diagnosis.