If you can see or feel an unusual swelling of veins next to a testicle, you might have a varicocele. Usually, a varicocele (sometimes spelled varicocoele) is harmless, but if you are in pain or having fertility problems, treatment can help.

What is a varicocele?

A varicocele (pronounced vari-co-seal) is a bunched network of veins in the scrotum, next to or above the testicle. Some people say it feels like a 'bag of worms'. It usually occurs near the left testicle but it can also occur on both testicles.

Usually, a varicocele develops in young children but it is often discovered from late adolescence onwards, when more blood flows to the testicles. Some men don’t notice it until later in life.

Symptoms of varicocele

You usually see a swelling, which is easier to notice when you're standing up.

Most men don't feel any pain. Sometimes, however, it can be painful or uncomfortable, especially after you exercise or in hot weather. Some men say they can feel a 'dragging' sensation, or that their testicle feels heavy.

A varicocele is usually harmless, but sometimes it can cause your testicle to shrink. It can also lead to infertility because the swelling and the heat coming from the blood interferes with the production of sperm.

Causes of varicoceles

A varicocele is caused by a problem in the network of veins that drain blood from the testicles.

Usually, valves in these veins stop the blood from coming back. If a valve is not working properly, the blood can leak backwards, forming pools. Eventually, the veins become larger than normal.

Varicoceles tend to run in families, so genetics might influence whether you develop one.

Sometimes, a kidney tumour might cause a varicocele to develop quickly. This is more common in older men.

If you notice any kind of lump in or near your testicles, you should see a doctor.

Diagnosis of a varicocele

Your doctor will examine your testicles while you are standing up. They might ask you to cough, which makes a varicocele easier to see.

Your doctor might also measure the temperature of your testicles.

If the lump is small, they might request an ultrasound so they can see the lump better.

Treatment for a varicocele

If you have no symptoms and no fertility problems, then you might not need any treatment.

If the varicocele is painful, if one testicle is smaller than the other, or if you are suffering fertility problems, your doctor might suggest treatment. There are two options.

One is an operation to tie or clip the veins. This is done by making a small incision in your abdomen or your groin under general anaesthetic. You might feel pain in the testicle for a few days.

The other option involves a technique called embolisation. This uses tiny metal coils to block the veins that are causing the problem. They are inserted through a tiny cut made in your skin, often in your groin, using a long, thin tube. This is done under local anaesthetic. Recovery is usually quick.

Sometimes, treating a varicocele can improve your fertility.

Talking about varicoceles

Talk to your partner, other family members, and your doctor about your symptoms. Your doctor will be able to rule out other more serious conditions, such as testicular cancer, if they examine you.

If you're worried about the possibility of infertility, discussing it with your partner and your doctor can help.

You could also use the healthdirect Question Builder tool to help you prepare for a medical appointment.

Check your symptoms using the healthdirect Symptom Checker for advice on what to do next.