A varicocele is the enlargement of the network of veins that drain the testicle in males.

What is going on in the body?

Blood flows from the scrotum and testicles through a complex of veins rather than a single vessel. These veins are prone to becoming enlarged or dilated. This frequently happens when the valves in the veins that keep the blood flowing in the direction of the heart become weakened. A varicocele is more common on the left because of the specific pattern of blood flow on that side. Varicoceles are linked to infertility in males 20 to 40% of the time. This is because the increased blood flow through the enlarged veins raises the temperature of the testicles and affects the development of sperm.

What are the causes and risks of the condition?

Approximately 15% of adult men have a small to moderate size left varicocele. Right-sided varicoceles are uncommon. Typically, the presence of a varicocele does not signal any type of serious disease. However, a large varicocele on the right side that appears suddenly may indicate a mass such as an enlarged lymph node or testicular cancer.