Varicocele

Key takeaways

• A varicocele is a group of enlarged veins in the scrotum, most commonly on the left side.
• Some men have no symptoms, while others notice aching, heaviness, visible veins, or fertility problems.
• Varicoceles can impair sperm production and semen quality in some men, but not everyone with a varicocele is infertile.
• Diagnosis usually involves a physical exam and sometimes a scrotal ultrasound.
• Treatment is not always necessary; it depends on symptoms, fertility goals, semen results, and testicular health.
• Common treatment options include surgical varicocelectomy or image-guided embolization.
• Improvement in semen parameters after treatment is possible, but results vary from person to person.
• Sudden right-sided varicocele, rapid onset swelling, severe pain, or a new scrotal mass should be evaluated promptly.

What is a varicocele?

A varicocele is the abnormal enlargement of the pampiniform plexus, a network of veins in the spermatic cord that helps drain blood from the testicle. When the valves in these veins do not function properly or blood flow is impaired, blood can pool, causing the veins to stretch and enlarge.

Varicoceles are one of the most common identifiable findings in male infertility. They are also frequently found in adolescents and adult men who are otherwise healthy. Many men live with a varicocele and never know it unless they are examined for a fertility issue, testicular discomfort, or a scrotal abnormality.

Although a varicocele can occur on either side, it is much more common on the left side. That is mostly due to differences in the way the left testicular vein drains into the larger abdominal veins, which can make pressure build-up more likely.

Another name for varicocele

There is not a widely used simpler medical synonym, but it is often explained as “varicose veins of the scrotum” or “enlarged testicular veins.”

Why a varicocele matters for men’s health and fertility

A varicocele matters because the testicles are highly sensitive to their environment, especially temperature and blood flow. The pampiniform plexus helps cool arterial blood before it reaches the testicle. When these veins become enlarged, that cooling system may work less efficiently. The resulting changes can affect testicular function.

Depending on the person, a varicocele may be linked with:

• Reduced sperm count
• Lower sperm motility
• Abnormal sperm shape or morphology
• Increased sperm DNA damage in some cases
• Smaller testicular size on the affected side
• Scrotal pain, pressure, or heaviness
• Possible lower testosterone production in some men

That said, a varicocele does not automatically mean infertility. Many men with a varicocele have normal semen analyses and can conceive naturally. The clinical question is whether the varicocele is actually affecting testicular function enough to justify treatment.

What causes a varicocele?

The exact cause is usually related to impaired venous drainage. In healthy veins, one-way valves help blood move back toward the heart. If those valves fail or pressure within the vein is high, blood can flow backward or pool in the scrotal veins.

Why they are more common on the left

Left-sided varicoceles are more common because the left testicular vein drains into the left renal vein at a different angle and often under higher pressure than the right side. This anatomy can make blood pooling more likely.

Potential contributing factors

• Vein valve dysfunction
• Anatomical differences in venous drainage
• Increased pressure in abdominal or pelvic veins
• Puberty-related growth and increased blood flow to the testicles

Most varicoceles are considered primary, meaning they arise from common vein anatomy and valve problems rather than a serious underlying disease.

When an underlying cause needs to be considered

A new-onset varicocele that appears suddenly, especially on the right side, may need more careful evaluation. Rarely, a blockage or mass in the abdomen can interfere with venous drainage. This is uncommon, but it is one reason a clinician may recommend imaging if the pattern is unusual.

Varicocele symptoms and signs

Many varicoceles cause no symptoms at all. When symptoms do occur, they often develop gradually.

Common symptoms

• Dull, aching scrotal pain
• Heaviness or dragging sensation in the scrotum
• Discomfort that gets worse after standing for a long time or exercising
• Visible enlarged or twisted scrotal veins
• A “bag of worms” feeling on exam or self-check
• One testicle appearing smaller than the other, particularly in younger males
• Infertility or abnormal semen analysis without obvious symptoms

When discomfort tends to worsen

Varicocele-related discomfort is often more noticeable:

1. Later in the day
2. After prolonged standing
3. After physical exertion
4. In warm conditions

Symptoms may ease when lying down because venous pressure decreases in that position.

What’s normal vs what’s not?

It is normal for the scrotum to vary slightly in size and for one testicle, often the left, to hang a bit lower than the other. What is not considered normal is a new cluster of enlarged veins, persistent ache, significant asymmetry, or fertility problems that suggest a testicular issue.

How a varicocele is diagnosed

Diagnosis usually starts with a medical history and physical exam. A clinician may examine the scrotum while you are standing and lying down, and may ask you to perform a Valsalva maneuver, which means bearing down as if exhaling forcefully with the mouth and nose closed. This can make an otherwise subtle varicocele easier to feel.

Common diagnostic steps

1. History: pain, fertility concerns, testicular size changes, duration of symptoms
2. Physical exam: inspection and palpation of the scrotum
3. Scrotal ultrasound: if the exam is unclear, to confirm the diagnosis or measure vein size and reflux
4. Semen analysis: if fertility is a concern
5. Hormone testing: sometimes used when testosterone or broader reproductive health is in question

What ultrasound can show

A scrotal ultrasound can identify enlarged veins and assess blood flow. It is especially helpful when:

• The physical exam is difficult or inconclusive
• The patient has a higher body mass index
• The concern is for a smaller, non-palpable varicocele
• There is a need to assess testicular size
• Other scrotal causes of pain need to be ruled out

Varicocele grades and severity

Clinicians often classify varicoceles by how easily they can be detected on physical exam.

Higher grade does not always mean worse fertility, but larger or palpable varicoceles are more likely to be clinically relevant than subclinical ones.

How varicocele can affect sperm, semen, and fertility

Varicocele is one of the most studied reversible causes of male infertility. The connection is real, but it is not absolute. Some men with a large varicocele have normal semen parameters, while others with a smaller one may have meaningful sperm impairment.

Ways a varicocele may affect fertility

• Higher scrotal temperature: sperm production works best slightly below core body temperature
• Oxidative stress: excess reactive molecules may damage sperm membranes and DNA
• Reduced oxygenation or altered blood flow: this may impair testicular function
• Hormonal disruption: changes in testosterone production or local signaling may play a role
• Accumulation of metabolic byproducts: this may affect the testicular environment

Semen parameters that may be affected

A varicocele may be associated with changes in:

• Sperm concentration
• Total sperm count
• Sperm motility
• Sperm morphology
• Semen volume less commonly, usually due to other factors
• Sperm DNA integrity in some men

Varicocele and infertility: important perspective

If a couple is having trouble conceiving, the presence of a varicocele does not automatically mean it is the sole cause. Fertility is shared between partners, and evaluation should usually include both members of the couple. A semen analysis is often one of the most useful next steps in determining whether the varicocele appears clinically important.

Who may benefit most from treatment for fertility reasons?

In general, treatment is more likely to be considered when a man has:

• A palpable varicocele on physical exam
• Documented infertility or subfertility
• Abnormal semen parameters
• A female partner with reasonable fertility potential or a shared plan for conception

Subclinical varicoceles found only on imaging are less clearly linked to benefit from repair in many cases.

Varicocele and testosterone

The testicles produce both sperm and testosterone. Some research suggests that varicoceles may impair the function of Leydig cells, which are involved in testosterone production. In some men, especially those with larger varicoceles or symptomatic disease, testosterone levels may be lower than expected.

Not every man with a varicocele has low testosterone, and not every man with low testosterone has a varicocele. But if symptoms such as low libido, reduced energy, erectile concerns, loss of muscle mass, or mood changes are present, a clinician may consider hormone testing as part of a broader evaluation.

Some men see testosterone improve after varicocele repair, but this is not guaranteed and should not be assumed in every case.

Varicocele treatment options

Treatment depends on symptoms, age, fertility goals, exam findings, semen results, and whether the affected testicle is smaller or losing function. Not all varicoceles need intervention.

When treatment may be recommended

• Persistent or bothersome pain
• Infertility with abnormal semen analysis and a palpable varicocele
• Testicular atrophy or reduced testicular growth in adolescents
• Possibly low testosterone in selected cases, after medical evaluation

Main treatment approaches

Microsurgical varicocelectomy

This is often considered a leading surgical approach because the microscope helps the surgeon identify and preserve arteries and lymphatic vessels while tying off abnormal veins. That can reduce the risk of recurrence and complications such as hydrocele formation.

Varicocele embolization

Embolization is a catheter-based procedure performed by an interventional radiologist. A small tube is threaded through a vein, and the abnormal testicular vein is blocked internally. This can be a good option for some men, including those who want to avoid surgery or who have had recurrence after prior repair.

How long it takes to see fertility-related changes

Sperm production takes time. If treatment improves semen parameters, that change may not be visible immediately. A repeat semen analysis is often checked after several months, since one full sperm production cycle takes roughly 2 to 3 months.

Possible risks and limitations of treatment

• Recurrence or persistence of the varicocele
• Hydrocele, which is fluid collection around the testicle
• Injury to surrounding structures, though uncommon with experienced care
• No guaranteed improvement in pain, sperm quality, or pregnancy outcomes

Can you improve a varicocele naturally?

There is no proven natural method that reliably makes a true varicocele disappear. Enlarged veins do not typically reverse through supplements, exercises, or home remedies alone. Still, some habits may help reduce discomfort or support overall reproductive health.

What may help symptoms or general testicular health

• Wearing supportive underwear if heaviness is bothersome
• Avoiding long periods of standing when possible
• Using over-the-counter pain relief if advised by a clinician
• Maintaining a healthy body weight
• Not smoking
• Limiting excessive heat exposure to the scrotum when trying to conceive
• Following a diet that supports cardiovascular and reproductive health

What to be cautious about

Claims that supplements, massage, detox programs, or “vein health” products can cure a varicocele should be treated skeptically. Some lifestyle changes may support sperm health broadly, but they are not a substitute for proper diagnosis or indicated medical treatment.

Questions to ask your doctor

If you have been told you have a varicocele, these questions can help you get a clearer plan:

• Is my varicocele palpable on exam or seen only on ultrasound?
• Do I need a semen analysis?
• Should my hormone levels, including testosterone, be checked?
• Is the affected testicle smaller than expected?
• Do you think this varicocele is likely contributing to pain or fertility problems?
• What are the pros and cons of observation versus treatment in my case?
• Which treatment approach do you recommend and why?
• How long after repair should I repeat semen testing?
• What are the chances of recurrence or no improvement?
• Should my partner also have a fertility evaluation?

Related tests and terms

Understanding a varicocele often involves a few related men’s health and fertility terms:

• Semen analysis: evaluates sperm count, motility, morphology, volume, and other features
• Sperm motility: how well sperm move
• Sperm morphology: the shape and structure of sperm
• Testosterone: the main male sex hormone
• Scrotal ultrasound: imaging test used to assess veins, blood flow, and testicular size
• Hydrocele: fluid around the testicle, which can sometimes be confused with other scrotal swelling
• Testicular atrophy: shrinkage of the testicle
• Azoospermia: no sperm seen in the ejaculate
• Oligospermia: low sperm concentration

Varicocele vs other scrotal conditions

Common myths and misconceptions

“A varicocele always causes infertility.”

False. Many men with varicocele can father children naturally and may have normal semen parameters.

“If it doesn’t hurt, it doesn’t matter.”

Not always. Some painless varicoceles are discovered only because of abnormal semen analysis or testicular size differences.

“All varicoceles should be repaired.”

No. Treatment decisions depend on symptoms, fertility goals, examination findings, and test results.

“Supplements can cure it.”

There is no strong evidence that supplements can reverse an anatomical varicocele.

“A right-sided varicocele is the same as a typical left-sided one.”

Right-sided varicocele can occur, but isolated new right-sided findings may warrant closer evaluation because they are less common.

When to seek medical advice

You should consider medical evaluation if you notice:

• A new lump, swelling, or enlarged veins in the scrotum
• Persistent scrotal aching or heaviness
• Trouble conceiving after regular unprotected intercourse
• One testicle becoming smaller than the other
• Low testosterone symptoms along with a suspected varicocele

Seek urgent care for:

• Sudden severe scrotal or testicular pain
• Rapid swelling
• Fever with scrotal pain
• Nausea or vomiting with acute testicular pain

These symptoms can suggest conditions other than a varicocele, including testicular torsion, which is a medical emergency.

FAQs

Is a varicocele dangerous?

Usually not in the sense of being life-threatening, but it can matter if it causes pain, testicular shrinkage, low testosterone symptoms, or fertility problems.

Can a varicocele go away on its own?

Most true varicoceles do not fully resolve on their own. Symptoms may fluctuate, but the enlarged veins usually remain unless treated.

Does varicocele mean I’m infertile?

No. A varicocele can be associated with impaired fertility, but many men with varicoceles still have normal sperm and can conceive naturally.

What does a varicocele feel like?

Some men feel nothing. Others notice a dull ache, heaviness, or a soft, twisted cluster of veins that can feel like a “bag of worms.”

Can varicocele cause low testosterone?

It may contribute in some men, especially when the varicocele is clinically significant, but it is not the only cause of low testosterone and should be evaluated in context.

Do I need surgery for a varicocele?

Not necessarily. Surgery or embolization is usually considered when there is pain, infertility with abnormal semen analysis, or evidence of testicular harm.

How is a varicocele confirmed?

Often by physical exam. If needed, a scrotal ultrasound can confirm enlarged veins and abnormal venous reflux.

Can exercise cause a varicocele?

Exercise does not usually cause a varicocele directly, but strenuous activity can make symptoms more noticeable by increasing abdominal pressure.

Is varicocele more common on the left side?

Yes. Left-sided varicocele is much more common because of how the left testicular vein drains into the abdominal venous system.

Will semen quality improve after varicocele repair?

It can improve in some men, but not in everyone. The degree of improvement depends on several factors, including baseline fertility status and the severity of testicular impairment.

References

• American Urological Association (AUA) and American Society for Reproductive Medicine (ASRM). Male infertility guideline and related guidance.
• European Association of Urology (EAU). Guidelines on sexual and reproductive health and male infertility.
• Urology Care Foundation. Patient education resources on varicocele and male infertility.
• Johns Hopkins Medicine. Varicocele overview and treatment information.
• Mayo Clinic. Varicocele: symptoms, causes, diagnosis, and treatment.
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Male reproductive health resources.
• Peer-reviewed reviews in journals such as Fertility and Sterility and European Urology on varicocele, semen quality, and male infertility.