Varicocele is defined as the abnromal dilatation of the testicular veins. It can be clinical (can be seen or felt by hand) or subclinical (detected by ultrasound).

Varicocele may cause detorioration of sperm count, motility and morphology. However, treatment of the varicocele by surgery has not been shown to increase the chances of pregnancy in women. Surgical treatment can only be recommended in men with pain due to varicocele, for cosmetic reasons, and in adolescents.