Varicoceles are varicose, or enlarged, veins in the scrotum. Varicoceles are usually found in adolescent boys on routine school or camp examinations and almost always produce no symptoms, although some boys complain of heaviness in the scrotum. Varicoceles appear in about 15 percent of adolescent boys worldwide. They usually appear in puberty and, because of anatomical differences in the way the veins leave the testicles on the right and left sides, varicoceles almost always develop in the veins that drain the left testicle.
Varicoceles are linked with stunted growth of the affected testicle and possible future infertility. Varicocele, the most common correctable cause of male infertility, is found in 30 to 50 percent of men with primary infertility. Varicocele repair can reverse the arrested growth of the testicle in adolescent boys and may protect their future fertility. It is important to note, however, that not all varicoceles have a negative impact on fertility.