Whilst doing cancer research. Found this on Home - Urology Care Foundation.
What are the causes and symptoms of penile injury?
The penis is much less frequently injured than other parts of the body such as the abdomen, legs, arms and head. However, it can be wounded as a result of various injuries, including automobile accidents, gunshot wounds, burns sexual activity and, in the case of mental disturbance, self-mutilation.
Perhaps the most common injury to the penis occurs during sexual activity. In the flaccid state, injury to the penis is rare because of the mobility and flexibility of the organ. During an erection, arterial blood flow causes the penis to be come rigid thus placing it at higher risk for injury. Although there is no bone in the penis, urologists frequently refer to the injury as a penile "fracture." During vigorous thrusting, the erect penis may accidentally slip out of the vagina. Due to the fast action, the penis strikes the outside of the woman instead of being reinserted into the vagina. The penis may then bend sharply despite the erection. A typical sign of this problem is a sharp pain in the penis joined by a "popping" sound. The pain and sound are produced by a rupture of the tunica albuginea, which is stretched tightly during the time of an erection. The pain may last for a short time or it may continue. The penis develops a collection of blood under the skin called a hematoma, which can distort the appearance of the penis (eggplant deformity). The injury is usually limited to one or both of the corpora cavernosa and, on rare occasions, the urethra.
The penis can also be injured by tearing the suspensory ligament, the structure that supports the organ at its base. Attached to the pelvic bone, this ligament can rip if an erect penis is pushed down suddenly causing pain and bleeding.
Further injuries can occur if a man places a rubber tube or other instrument around the base of the penis that is too tight or on for too long. Cutting off the blood supply, it can produce a wound known as a strangulation lesion. Also, if an object is inserted into the urethra, both it and/or the penis can be injured.
Umm worrying.