The penis and testicles are part of the male reproductive system. The testicles produce semen and testosterone and are held in the bag of skin, called the scrotum, behind the penis. The external organ is the penis, which carries semen and urine. Numerous diseases, conditions and injuries may occur to the area that may lead to testicular and penile pain or discomfort.
According to MayoClinic.com, a scrotal mass may be caused by abnormal tissue growth, accumulation of fluid in the scrotum, or swollen and hardened contents of the scrotal sac. Pain or tenderness may be present in either testicle. Causes include testicular cancer, hydrocele or sac of fluid encasing the testicles, or infection such as the mumps.
A prolonged erection of the penis that occurs without sexual arousal or stimulation is called priapism. According to MayoClinic.com, it is painful and lasts for over four hours. If left untreated, it may lead to serious damage of the penis and the inability to sustain an erection. A prolonged erection is caused by changes of penile blood flow. Contributing factors include injury, diabetes, diseases of the nervous system and certain blood disorders, such as sickle cell anemia and leukemia. Priapism may also be a side effect of medications, such as Viagra, for erectile dysfunction.
Sexually transmitted diseases, or STDs, infect the genital area. Stanford University lists the following STDs that may cause penile and testicular pain or discomfort: gonorrhea, which causes painful urination; chlamydia, which causes itching and discomfort at the opening of the penis; chancroid, which causes boils or penile sores; genital herpes, which involves blistering of the penis; and human papillomavirus, which manifests in penile lesions that are painful with intercourse.
Testicular torsion occurs when one of the testicles rotates in the scrotum. This rotation causes twisting of the spermatic cord that supplies blood to the testicles. MayoClinic.com lists symptoms as sudden pain in one of the testicles and abdomen, swelling of the scrotum, nausea and vomiting. This is a serious condition, and if left untreated, it may cause loss of the testicle or inability to father children. Immediate emergency treatment is needed even if the testicle untwists on its own.
MayoClinic.com describes an inguinal hernia as the protrusion of the intestine through a weak area of the lower abdomen. The condition is not necessarily serious, but the complications can be life threatening. If the intestine protrudes through the abdominal wall into the scrotum, pain and swelling occur in the testicles. Medical attention is needed for this condition.