The inability to pass urine in the bladder is called urinary retention. If urine is completely retained in the bladder, it is called complete urinary retention. If there is still residual urine after urination, it is called incomplete urinary retention. The acute onset is called acute urinary retention, and the bladder is swollen and painful when acute urinary retention occurs, and urine cannot be discharged; the slow onset is called chronic urinary retention, when there is often no pain and often a small amount of continuous urination, also called pseudo-incontinence. I. The causes of urinary retention are divided into two categories: 1, urethral obstruction: urinary retention can be caused by obstruction of the urethra due to inflammatory edema or stones, urethral stricture, urethral trauma, prostate hypertrophy or tumor, acute prostatitis or abscess, bladder tumor, etc. 2, neurological factors: various causes of central nervous disorders and diabetes and other causes of plant nerve damage can cause urinary retention. Second, urinary retention can be secondary to other diseases, mainly in: 1, secondary to urinary tract infection: because urinary retention is conducive to bacterial reproduction, it is easy to complicate urinary tract infection, which is difficult to cure and easy to recur, accelerating the deterioration of kidney function. For example, men with prostatic hypertrophy and women with urethral stricture often have partial urinary retention, but they have no conscious urinary disorder. Early consultation and treatment is needed for such patients to remove residual urine, effectively control urinary tract infections and protect renal function. 2, secondary reflux nephropathy: due to urinary retention, the pressure in the bladder rises and urine refluxes along the ureter, causing pelvic effusion, followed by renal parenchyma compression, ischemia and even necrosis, which finally leads to chronic renal failure.