Difficulty in holding urine with an underfilled bladder can be associated with physiologic or pathologic factors, and pathologic factors may include diseases such as prostatic hyperplasia or bladder tuberculosis. 1. Physiological factors: before the imaging examination, due to insufficient water consumption or holding urine for too short a period of time, the urine volume in the bladder is low, can be found in poor bladder filling. 2. Pathological factors: such as prostate hyperplasia, due to bladder outlet obstruction, in order to overcome the resistance to urination, long-term can lead to high pressure in the bladder, forced urethral muscle degeneration, there is an unstable contraction, which can lead to urge urinary incontinence, urinary frequency, urinary urgency and other manifestations of the difficulty of holding urine. In addition, bladder tuberculosis can lead to diffuse fibrosis of the tissue, bladder contracture occurs, there can be frequent urination, incontinence performance. There are other diseases can cause poor bladder filling difficulty in holding urine, the corresponding symptoms should be timely medical care, clear cause, targeted treatment.