An enlargement of the veins in the scrotum, similar to a varicose vein you might see in your leg. They’re a common cause of low sperm production and decreased sperm quality, which can impact fertility and risk of miscarriage. However, not all varicoceles affect sperm production, and many don't need treatment. If a varicocele causes symptoms such as a very sharp or dull discomfort, it often can be repaired surgically.

Juliana Kassianos