Since the scrotum and penis are not protected by bony structures, an injury can occur fairly easily. An injury to the genitals often causes moderate to severe pain. Usually the pain goes away quickly, and no permanent damage occurs.
Forceful blows to the penis or scrotum can damage genital tissues. The tissues of the penis can tear if the penis is hard (erect) when it is struck or if the injury occurs during vigorous sexual activity. A very forceful blow to a testicle can rupture the testicle, causing immediate pain and swelling.
A straddle injury from a bicycle or a fall or a zipper injury to the penis may cause mild to moderate pain. Home treatment can help relieve pain after a minor injury to the scrotum or penis.
More serious symptoms that do not go away after an injury need to be evaluated by a health professional. These symptoms include:
WebMD Medical Reference from Healthwise