Varicocele: Enlarged Scrotal Veins Explained

A varicocele is a cluster of widened veins in the scrotum, just above and behind the testicle. It is a bit like a varicose vein in the leg. Varicoceles are common, and many men have one without knowing. Some cause a dull ache, and some are linked to fertility problems. This guide explains what a varicocele is, why it happens, how doctors grade it and when treatment is worth considering.

What is a varicocele?

Each testicle hangs on a cord that carries its blood supply. Blood drains out of the testicle through a mesh of small veins called the pampiniform plexus, which then joins the main testicular vein running up into the tummy.

A testicular varicocele forms when these veins stretch and swell. Large ones can be seen through the skin and feel soft and lumpy, often compared to a “bag of worms”. Smaller ones can only be felt, and the smallest show up only on an ultrasound scan.

How common are varicoceles?

Varicoceles are found in about 15% of men. They often first appear around puberty, when blood flow to the testicles increases, and they tend to stay into adult life. They are much more common in men having trouble conceiving. Studies find a varicocele in up to about 35% of men with primary infertility, meaning men whose partner has never become pregnant.

What causes a varicocele?

Like leg veins, the testicular veins have small one-way valves. If the valves do not close properly, blood falls back down towards the testicle instead of flowing up to the heart. The veins around the testicle then fill, stretch and twist.

Why most are on the left

A left varicocele is by far the most common type. The left testicular vein is longer than the right one, and it joins the left kidney vein at a right angle, which makes backflow more likely. In some men the left kidney vein is also squeezed between two arteries, a problem called nutcracker syndrome, which raises the pressure further.

Right-sided and bilateral varicoceles

Bilateral varicoceles, on both sides, are less common. A right varicocele on its own is unusual, because the right vein drains straight into the large vein of the abdomen. If you have a right-sided varicocele only, or a varicocele that appears suddenly later in life, your doctor may arrange a scan of the tummy to make sure nothing is pressing on the veins higher up.

Symptoms

Many varicoceles cause no symptoms and are found during a routine check or fertility tests. When there are symptoms, they may include:

• A soft, lumpy swelling above the testicle, often on the left
• A dull, dragging or heavy ache in the scrotum
• Discomfort that is worse after standing, exercise or a long day, and eases when lying down
• A swelling that gets smaller when you lie down and bigger when you stand or strain
• A testicle that is smaller on the affected side

More detail is in our guide to varicocele symptoms.

Varicocele grades

Doctors usually grade a varicocele by how easy it is to find:

• Grade 0 (subclinical). Only seen on ultrasound. It cannot be felt.
• Grade 1. Small. It can only be felt when you hold your breath and bear down.
• Grade 2. Medium. It can be felt while standing without bearing down, but cannot be seen.
• Grade 3. Large. It can be seen through the skin of the scrotum.

The grade helps guide decisions, but it is not the whole story. A small varicocele can still ache, and a large one may cause no trouble at all. An ultrasound scan can confirm the diagnosis and check the testicles.

Varicoceles and fertility

The testicles work best when they are a little cooler than the rest of the body. Pooled blood around the testicle may warm it and may affect sperm production. That is one reason a varicocele can be linked to a lower sperm count or poorer sperm quality.

But a varicocele does not mean you are infertile. Many men with one father children with no treatment. Fertility specialists usually only suggest treating it when a couple is having difficulty conceiving, the varicocele can be felt, and a semen test is abnormal. Read more about how varicoceles can affect fertility.

Will a varicocele go away?

A varicocele usually does not go away on its own, but most stay stable and never need treatment. Supportive underwear, rest and simple pain relief can help with a mild ache.

When is treatment considered?

Treatment is not needed just because a varicocele is there. Doctors usually consider it for:

• Ongoing pain or discomfort that affects daily life
• Fertility problems with an abnormal semen test
• A teenager whose testicle on the affected side is not growing as it should

Surgery or embolisation?

There are two main ways to treat a varicocele, and both aim to close off the faulty veins so blood drains through healthy ones:

• Surgery (varicocelectomy). A surgeon ties off the faulty veins through a small cut in the groin or lower tummy, often using a microscope, or by keyhole surgery. It usually needs a general anaesthetic.
• Embolisation (embolization). An interventional radiologist passes a thin tube into a vein, usually in the groin, neck or arm, and guides it to the testicular vein using X-ray. The vein is then blocked from the inside with tiny coils or a sealing foam. It is usually done under local anaesthetic with or without light sedation, and most men go home the same day.

Both work well for most men, and each has different risks, recovery times and chances of the varicocele coming back. The right choice depends on your anatomy, your goals and local expertise. Compare the options in our guides to varicocele treatment and varicocele embolisation.

Is it related to pelvic congestion in women?

Yes. A varicocele is the male version of the same problem that causes pelvic congestion syndrome in women, where faulty valves in the ovarian veins let blood pool in the pelvis. A Singapore vascular surgeon’s guide to pelvic congestion syndrome describes the female equivalent.

When to see a doctor

Always get a new lump or swelling in the scrotum checked by a doctor. Most lumps are not serious, but a doctor needs to examine you to rule out other causes, including testicular cancer. Also see a doctor if you have a lasting ache in the scrotum, a testicle that looks smaller, or difficulty conceiving after a year of trying.

Sudden, severe pain in a testicle is an emergency. It can be a sign of testicular torsion, where the testicle twists and loses its blood supply, and it needs treatment within hours. Get urgent help too for testicle pain with vomiting or tummy pain, or a hot, red, swollen scrotum with fever. In Singapore, call 995 in an emergency.

This article is general information, not personal medical advice. Please speak to a doctor about your own symptoms. How we create our content.