Varicoceles are very common and occur in 10 to 15 of every 100 adolescent and teenage boys though it’s not understood why it occurs in one boy and not another. Most males with a varicocele have no symptoms.

Varicoceles form during puberty, and can grow larger and easier to notice over time; they are more common on the left side of the scrotum. This is because the male anatomy isn't the same on both sides. Varicoceles can exist on both sides at the same time, but this is rare.

Many causes of varicoceles have been offered. The valves in the veins may not work well (or may be missing). If blood flow is sluggish, blood may pool in the veins. Also, the larger veins moving from the testicles towards the heart are connected differently on the left and right side so more pressure is needed on the left side to keep blood flowing through the veins towards the heart. If blood flows backwards or pools in the veins, that can cause them to swell. Rarely, swollen lymph nodes or other abnormal masses behind the abdomen block blood flow. This can lead to sudden swelling of the scrotal veins.

What Problems Do Varicoceles Cause?

Varicoceles are a concern for many reasons. Some may cause infertility (problems fathering a child) and slow growth of the left testicle during puberty. Varicoceles may be the cause of fertility problems in about 4 out of 10 men who have problems fathering their first child. The effect on fertility appears to worsen with time; however, in most men the affect may occur so late in life (e.g., 60 or 70 years old) that they don’t know it has happened or are not concerned with fertility.


Varicoceles can be corrected by a relatively simple surgical procedure. The only absolute reason to correct a varicocele is if a man is already infertile. Because the harmful effect of a varicocele seems to increase with time, it might be possible to prevent infertility if the varicocele is treated early, before infertility occurs.

The challenge doctors have is that they cannot identify which teenager with a varicocele is going to be infertile as an adult.

Pediatric urologists follow boys with varicoceles to see how the testis is growing. When the patient reaches full adult development at age 18, an analysis of the semen can be performed. If it were abnormal at that time, correction of the varicocele would be recommended. If the analysis is normal, it tells us that the patient is fine at that time, but it doesn’t indicate how he will be later in life as the effect of the varicocele progresses.

The most common way a varicocele is corrected is by surgical division of the blood vessel somewhere above the scrotum. This is an outpatient procedure done either by an incision in the groin or lower abdomen, or by laparoscopic surgery. In some instances, parents will elect to have the varicocele treated by having a catheter placed into the main vein to the heart (the inferior vena cava). The catheter is then fed back down the “bad” vein and a solid material is injected down the vein to block it. Both of these are very effective at correcting the varicocele.