What is a varicocele?

Varicoceles (VAIR-ick-oh-seals) are a common disorder of the veins inside the scrotum, the protective sac that protects and holds the testicles (balls). If you have a varicocele, it means veins inside the scrotum are enlarged (wider than they should be).

Varicoceles are similar to varicose veins, a common condition that causes veins in the leg to swell and lose their shape.

Varicoceles are usually painless but can sometimes cause aching testicles or pain that may come and go. In some people, a varicocele can affect fertility. If a varicocele doesn’t bother you, you may not need treatment.

How common are varicoceles?

Varicoceles affect 15% to 20% of all men and people assigned male at birth in the U.S. — about 1 in 5. In most people who have a varicocele, it occurs on the left side. Less commonly, it can sometimes affect the right-sided scrotum or both sides.

Who gets varicoceles?

Varicoceles can happen to anyone with testicles, at any age. Healthcare providers believe many cases are congenital (present at birth). Often, people notice a varicocele during the teenage years. Medical experts suspect this timing has to do with puberty, when blood flow to the genitals increases. Sometimes the varicocele can prevent the testicle from growing properly.

What causes varicoceles?

Much remains unknown about why varicoceles develop. It may be that varicoceles occur due to a faulty “switch” (or valve) inside certain veins in the spermatic cord, a band of tissues that holds the testicles in place.

These veins move blood from the testicles to the rest of the body. The valve acts as an “on/off switch.” When a valve doesn’t work the way it should, excess blood may build up inside testicular veins. Over time, this malfunction causes veins to swell.

What are the symptoms of varicoceles?

A varicocele often causes no symptoms. You may notice:

What does a varicocele feel like?

Varicoceles may cause mild discomfort, aches or pain, usually in the left testicle. Larger, swollen veins in the scrotal sac often feel or look like a bag of worms (or spaghetti). A small varicocele may be too small to see or feel.

Can varicoceles affect male infertility?

The short answer is yes: Varicoceles affect male fertility in some people. However, many people with varicoceles experience no reproductive obstacles.

Medical experts don’t understand exactly what role varicoceles play in male infertility. It’s possible that temperature changes inside the scrotum due to blood buildup in veins. This higher temperature may affect sperm count or production.

If you suspect infertility might be an issue for you, talk to your healthcare provider. Fertility concerns are the top reason people get treated for varicoceles. Almost half of couples who seek medical care for male infertility have a varicocele.

Last reviewed by a Cleveland Clinic medical professional on 10/08/2020.


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