Varicocele Infertility: Sperm, Testosterone, Erections and Whether Repair Helps

If you have been told you have a varicocele while trying for a baby, it is natural to wonder whether it is the problem. Varicocele infertility is a real link, but it is not as simple as “varicocele equals infertile”. This guide explains how a varicocele can affect sperm, testosterone and erections, what the evidence says about repair, and when to see a fertility specialist.

If you are new to the condition, start with our varicocele overview.

Can a varicocele cause infertility?

A varicocele is a cluster of widened veins above the testicle. Faulty valves let blood fall back and pool around the testicle instead of draining away.

Researchers still do not fully understand how this affects fertility. The main ideas are:

• Heat. Sperm production works best a little below body temperature. Pooled blood may warm the testicle.
• Oxidative stress. Pooled blood may expose the testicle to harmful by-products that damage sperm and their DNA.
• Reduced testicle growth. In some boys and young men, the testicle on the affected side grows less well.

The result can be a lower sperm count, poorer sperm movement, more abnormally shaped sperm or more DNA damage. But this does not happen to every man. Many men with a varicocele have a normal semen test and become fathers without any treatment.

How common is varicocele infertility?

Figures from European urology guidelines give a sense of the link:

• About 15 in 100 men in the general population have a varicocele
• About 25 in 100 men with an abnormal semen test have one
• About 35 to 40 in 100 men who see a doctor about infertility have one

So varicoceles are more common in men with fertility problems. That shows a link, but it does not prove the varicocele is the cause in any one man. Other factors in both partners often play a part.

Does treating a varicocele improve fertility?

This is the key question, and the honest answer is “sometimes, for the right man”.

Semen results

Semen results improve in many men after repair, whether by surgery or embolisation. Because new sperm take about three months to develop, doctors usually repeat the semen test three to six months after treatment.

Pregnancy and live births

A better semen test is not the same as a baby. A 2021 Cochrane review pooled 48 randomised trials. It found that treatment may improve the chance of pregnancy compared with no treatment or delayed treatment. In the trials, about 21 in 100 couples without treatment became pregnant, compared with an estimated 22 to 48 in 100 after treatment.

However, the review was uncertain whether treatment increases live births, because only two small trials measured this and their results pointed in different directions. The certainty of the evidence was rated low or very low. The review also could not say whether surgery or embolisation works better for fertility. It did find that microsurgery through a small groin cut probably gives slightly higher pregnancy rates and fewer recurrences than other surgical methods.

Who is treatment advised for?

European Association of Urology (EAU) guidelines recommend treatment when all of these apply:

• The varicocele can be felt on examination (a “clinical” varicocele)
• The semen test is abnormal
• There is no other clear cause of the couple’s infertility, and the female partner’s fertility is good

The same guidelines advise against treatment if the semen test is normal, or if the varicocele can only be seen on a scan. Repair may be considered in men with high levels of sperm DNA damage, and in some men with no sperm in the semen, but the evidence there is weaker. In teenagers, the main reason to treat is a testicle that stays clearly smaller than the other on repeat checks.

Our guide to what your varicocele grade means explains the difference between a varicocele that can be felt and one seen only on ultrasound.

Repair or go straight to IVF?

Time matters, especially if the female partner is older. For some couples, going straight to IVF or ICSI (where a single sperm is injected into an egg) is quicker than waiting months to see if repair works. Some studies suggest repair before ICSI may improve results, but this evidence is mainly from older, non-randomised studies. This is a decision to make with a fertility specialist, looking at both partners.

Varicocele and low testosterone

The testicle makes testosterone as well as sperm. Some men with a large varicocele have lower testosterone levels, possibly because the same pooled blood affects the cells that make the hormone.

Several reviews have found that testosterone tends to rise after repair. In a 2017 analysis, the rise was small overall and clearer in men whose level was low before treatment. A 2026 review of men with low testosterone found a similar pattern. Most of these studies were not randomised, so the results should be read with caution.

European guidelines say repair may be considered for men with low testosterone and a varicocele that can be felt, while noting that better trials are still needed.

One important point: testosterone treatment can switch off sperm production. If you are trying for a baby, talk to a specialist before starting any testosterone product.

Varicocele erectile dysfunction: is there a link?

People often search for “varicocele erectile dysfunction”, but a varicocele is not a common direct cause of erection problems. Erections depend on healthy blood vessels, nerves and hormones, and on how you feel. Common causes of erectile dysfunction include:

• Blood vessel disease, high blood pressure, diabetes and smoking
• Some medicines
• Stress, anxiety and relationship strain, including the stress of trying to conceive
• Low testosterone

Some small studies report modestly better erection scores after varicocele repair, mostly in men with low testosterone. The evidence is limited. Repair is not a recognised treatment for erectile dysfunction on its own. Erection problems can be an early sign of heart and blood vessel disease, so they are worth a check-up in their own right.

Does the type of treatment matter?

The two main options are microsurgical varicocelectomy, where a surgeon ties off the faulty veins through a small groin cut, and embolisation, where the vein is blocked from the inside through a needle hole. Microsurgery has the lowest reported recurrence and the strongest fertility evidence. Embolisation avoids a cut and has a quicker recovery. Compare them in our guides to varicocele treatment options and varicocele embolisation.

When to see a fertility specialist

Fertility is a couple’s issue, and both partners should be checked. See a doctor if:

• You have been having regular unprotected sex for a year without a pregnancy
• The female partner is in her mid-thirties or older, in which case go sooner rather than waiting a full year
• You already know of a possible problem, such as a varicocele, a smaller testicle, past testicle surgery or treatment for cancer

For men, the first test is usually a semen analysis, often repeated if abnormal. A doctor will also examine you, and may arrange a scrotal ultrasound and hormone blood tests. You can see a urologist or a fertility (reproductive medicine) specialist. Our guide to finding a specialist explains who does what.

When to see a doctor urgently

Always get a new lump or swelling in the scrotum checked by a doctor, even if you think it is a varicocele. A testicle that feels hard, or has a firm lump in it, needs prompt review.

Sudden, severe pain in a testicle is an emergency. It may be testicular torsion, where the testicle twists and loses its blood supply, and it needs treatment within hours. Get urgent help too for 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.