Urinary extravasation is mostly seen in men and is divided into two categories: open and closed, which are common urological emergencies. Open urinary extravasation is mostly due to shrapnel and sharp force injuries. Closed urinary extravasation is a direct result of contusions, lacerations, or intracavitary instruments. There are many causes of urinary extravasation, see the following introduction for details: 1. Injury in the urethra: The vast majority of injuries occur when applying transurethral instrumentation or expelling foreign bodies (such as stones). A small number of sexual perversion, intoxication or psychiatric patients with hair needles, wire, glass dry and other foreign objects into the urethra and cause injury, misinjection of certain chemicals such as silver nitrate, copper sulfate, carbolic acid, etc. can cause chemical burns. Electric burns to the urethra can be caused when performing electrodesection via the urethra. 2, violence outside the urethra injury: this injury is more common than the urethra injury. Can be penetrating injuries or closed injuries. The former is mainly seen in the battlefield, the urethra by firearms or sharps penetration. Most of the injury sites are in the bulb and membrane. The corpus cavernosum and prostate are less common. Closed urethral injuries can be seen in both wartime and peacetime. Injuries to the perineum are most often seen in the ball and membrane urethra when the perineum is jockeyed or kicked, and with pelvic fractures, often with urethral injuries to the prostate.