Varicocele

Overview

• A varicocele is an enlargement of the veins inside the scrotum (the sac that holds the testicles), similar to varicose veins that can occur in the legs
• It most often develops on the left side and is usually harmless, but in some men it can cause discomfort or affect fertility

How does a varicocele happen?

• Veins carry blood away from the testicles back towards the heart, using one-way valves to keep blood flowing in the right direction; when these valves do not work properly, blood can pool and collect in the veins, causing them to widen and become a varicocele
• The left testicular vein joins a larger vein at an awkward angle, which makes it more prone to this kind of backflow, this is why varicoceles are far more common on the left side

How common is varicocele?

• Varicocele affects around 15 in every 100 men in the general population
• It is found in up to 40 in every 100 men being investigated for fertility problems
• It most commonly first develops during puberty, typically between the ages of 10 and 25 years

Who is commonly affected?

• Teenage boys and young men, especially during or shortly after puberty
• Men undergoing evaluation for difficulty conceiving
• It occurs on the left side in the large majority of cases, though it can occasionally affect both sides

What causes varicocele?

• Faulty one-way valves within the veins of the scrotum, allowing blood to pool and the veins to widen over time
• The anatomy of the left testicular vein, which drains at an angle that increases pressure within the vein
• The exact reason some men develop this valve weakness while others do not is not fully understood

Symptoms of varicocele

• Often no symptoms at all; many varicoceles are found by chance during a routine check-up or a fertility evaluation
• A dull ache or feeling of heaviness in the scrotum, often worse after standing for long periods or physical activity and easing when lying down
• A swelling above the testicle that has been described as feeling like a “bag of worms”
• Visibly enlarged veins in the scrotum in more noticeable cases
• A smaller testicle on the affected side over time, in some cases

Warning signs that need prompt medical attention

• Sudden, severe testicular pain, this could indicate testicular torsion (twisting of the testicle), which is a medical emergency
• A varicocele that appears suddenly, especially on the right side only or one that does not reduce when lying down
• Noticeable shrinking of the testicle on the affected side

Diagnosis and investigations

• Physical examination: your doctor will feel the scrotum while you are standing and may ask you to bear down (Valsalva manoeuvre) to make the varicocele more obvious
• Scrotal ultrasound with Doppler: confirms the diagnosis, measures the width of the veins and checks the direction of blood flow
• Semen analysis: recommended if you and your partner are having difficulty conceiving

Understanding the grades of varicocele

• Grade I: Small; only felt when bearing down
• Grade II: Moderate; felt without needing to bear down
• Grade III: Large; visible through the skin without needing to touch it

Treatment options

Not every varicocele needs treatment. If it is not causing pain and fertility is not a current concern, your doctor may simply recommend monitoring it over time.

Surgery (varicocelectomy)

• The affected veins are tied off so that blood is redirected through healthy veins nearby
• Can be performed as open surgery, laparoscopic (keyhole) surgery or microsurgery
• The microsurgical approach generally has the lowest rates of recurrence and complications

Percutaneous embolization

A minimally invasive procedure performed by a radiologist, in which a thin tube (catheter) is used to block the affected vein from the inside, without the need for a surgical cut in the scrotum.

Supportive care

• Pain relief medicines for mild discomfort
• Supportive underwear to ease heaviness or aching

When is treatment needed?

• Persistent scrotal pain that affects daily activities or quality of life
• Difficulty conceiving, where semen analysis shows abnormalities linked to the varicocele
• In adolescents, evidence of the affected testicle failing to grow normally compared with the other side
• All treatment decisions are made jointly with you, weighing the benefits, risks and your personal circumstances

Impact on fertility

• Varicocele is one of the more common and treatable causes of male infertility, but many men with a varicocele have entirely normal fertility
• It is thought to affect fertility by raising the temperature around the testicles, which can reduce sperm quality
• Treating the varicocele can improve semen quality in some men, though it does not guarantee a pregnancy will follow

Can varicocele be prevented?

• There is no proven way to prevent a varicocele from forming, since it develops because of the anatomy of the veins rather than lifestyle choices
• General reproductive and vascular health, a healthy weight, regular exercise and not smoking, all these supports overall fertility and vein health
• Because varicoceles most often start during puberty, some clinicians recommend a routine testicular self-check or a school-age physical examination so that any changes in testicle size are picked up early

Lifestyle and self-care

• Wear supportive underwear or an athletic supporter, particularly during exercise
• Avoid standing for long periods where possible
• Applying a cold compress to the area can ease discomfort
• Avoid heavy lifting or straining, which can make symptoms feel worse
• Maintain a healthy weight and stay physically active as part of general reproductive health

Long-term care

• If being monitored without treatment, regular follow-up is important, especially in teenagers, to track testicular growth
• Men treated for fertility reasons are usually followed up with repeat semen analysis
• Report any new or worsening pain, swelling or changes in testicle size promptly

Testicular self-awareness

Getting familiar with the normal size, shape and feel of your testicles makes it easier to notice changes early, whether related to a varicocele or another condition.

• The best time to check is after a warm bath or shower, when the scrotal skin is relaxed
• Gently roll each testicle between the thumb and fingers, feeling for lumps, swelling or changes in size
• It is normal for one testicle to sit slightly lower than the other and for the left side to feel a little different from the right
• If you notice a new lump, swelling, heaviness or a change in size, arrange to see your doctor

When to contact a doctor?

• A new lump, swelling or heaviness in the scrotum
• Persistent scrotal discomfort that does not settle
• Difficulty conceiving with your partner after a year of trying
• Sudden, severe testicular pain, this needs emergency care

Myths and facts

Myth 1: Every varicocele needs surgery.

Fact: Most varicoceles cause no symptoms and do not require treatment. Many are simply monitored over time.

Myth 2: A varicocele always causes infertility.

Fact: Many men with a varicocele father children without any difficulty. It is only one of several possible contributing factors to fertility problems.

Myth 3: Varicocele is caused by an infection or a sexually transmitted infection.

Fact: A varicocele is caused by faulty vein valves and has nothing to do with infection or sexual activity.

References

1. NHS. Varicocele [online]. Available from: https://www.nhs.uk/conditions/varicocele/. Accessed on 16 July 2026.
2. Mayo Clinic. Varicocele — symptoms and causes [online]. Available from: https://www.mayoclinic.org/diseases-conditions/varicocele/symptoms-causes/syc-20378771. Accessed on 16 July 2026.
3. Urology Care Foundation (American Urological Association). What is a Varicocele? [online]. Available from: https://www.urologyhealth.org/urology-a-z/v/varicocele. Accessed on 16 July 2026.
4. Cleveland Clinic. Varicocele [online]. Available from: https://my.clevelandclinic.org/health/diseases/15653-varicocele. Accessed on 16 July 2026.
5. Mayo Clinic. Varicocele — diagnosis and treatment [online]. Available from: https://www.mayoclinic.org/diseases-conditions/varicocele/diagnosis-treatment/drc-20378775. Accessed on 16 July 2026.
6. American Society for Reproductive Medicine (ASRM). Varicocele fact sheet [online]. Available from: https://www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/. Accessed on 16 July 2026.