The main reason for this situation is divided into two main categories: first, the presence of acute or chronic urinary retention, due to a variety of factors that cause the patient’s urine in the bladder, not able to discharge the body, the need to retain a catheter to drain the urine, according to the different causes to choose the appropriate strategy, such as prostatic hyperplasia can be performed via The first is that the prostate can be drained by a catheter. Secondly, there is no residual urine in the bladder, but there is still a feeling of wanting to urinate, most of which is due to prostate related diseases or overactive bladder disorder, etc. There are also some patients with inflammatory conditions that require detailed examination to deal with these etiologies.