Varicocele and Testosterone: What the Evidence Shows

Varicocele — an abnormal enlargement of the pampiniform plexus of veins in the scrotum — is the most commonly identified correctable cause of male infertility. It affects approximately 15% of the general male population and is found in 35–40% of men presenting for infertility evaluation. [^world1992]

The connection between varicocele, testosterone, and sperm quality is real and mechanistically understood. The good news is that it is also largely reversible.

What a Varicocele Does to the Testicle

The primary mechanism of harm is heat. Testicular function depends on a temperature approximately 2–4°C below core body temperature — which is why the testes are located outside the body cavity. Varicoceles impair the countercurrent heat exchange mechanism that keeps the testes cool, leading to elevated scrotal temperature.

Consequences of chronic testicular heat stress:

• Impaired spermatogenesis (sperm production)
• Increased oxidative stress in testicular tissue
• Damage to Leydig cells (the testosterone-producing cells)
• Elevated reactive oxygen species damaging sperm DNA

The result is a characteristic pattern: reduced sperm count, impaired motility, increased abnormal morphology, and — often — reduced testosterone production from the affected testicle.

Varicocele Grades

Varicoceles are classified by physical examination and ultrasound:

Grade III varicoceles have the greatest impact on testicular function. Left-sided varicoceles are significantly more common than right-sided (due to the angle at which the left testicular vein drains into the left renal vein). Bilateral varicoceles affect 10–20% of men with the condition.

Testosterone and Varicocele

Varicocele impairs Leydig cell function, reducing testosterone production in the affected testicle. The effect on serum testosterone depends on varicocele grade and duration, but the relationship is well-documented.

Studies consistently show that men with varicoceles have lower serum testosterone levels than age-matched controls, independent of other factors. The reduction is most pronounced in men with bilateral varicoceles and high-grade unilateral disease. [^mo2009]

The mechanism: Leydig cells are sensitive to heat-mediated oxidative damage. Chronic scrotal hyperthermia reduces the number of functioning Leydig cells and impairs steroidogenic enzyme activity, reducing the testicular contribution to total testosterone.

Does Treatment Restore Testosterone?

Multiple studies and meta-analyses support testosterone improvement following varicocele repair. A systematic review by Hsiao and Goldstein found that varicocelectomy improved total testosterone in the majority of studies analyzed, with mean increases of 100–200 ng/dL in hypogonadal men with clinical varicocele. [^abdelbaki2017]

Key factors predicting testosterone response:

• Pre-operative testosterone level: Men with lowest baseline testosterone show greatest proportional improvement
• Varicocele grade: Higher-grade varicoceles produce larger post-repair improvements
• Age: Younger men with recent onset tend to show greater recovery
• Bilateral repair: Bilateral varicocelectomy produces larger testosterone gains than unilateral repair in bilateral disease

The testosterone improvement typically develops over 3–6 months post-repair, consistent with the timeline of Leydig cell recovery. [^zohdy2011]

Men with clinical varicocele and low testosterone should consider varicocele repair before initiating testosterone replacement therapy — TRT will suppress endogenous production and may not be necessary if the varicocele is the primary cause.

Fertility Outcomes

The fertility impact of varicocele repair is more studied than the testosterone effects. A Cochrane meta-analysis and multiple systematic reviews confirm that varicocelectomy improves semen parameters:

• Sperm concentration: Increases in approximately 60–70% of men post-repair
• Motility: Improves in the majority of treated men
• Morphology: Shows improvement, though less consistently than concentration and motility
• Natural pregnancy rates: Increased compared to untreated controls

A meta-analysis by Agarwal et al. found significant improvements in sperm concentration, motility, and morphology across 17 studies following varicocelectomy. [^agarwal2007] A larger meta-analysis by Baazeem et al. confirmed spontaneous pregnancy rates of approximately 33% at one year post-repair — approximately double the untreated rate. [^baazeem2011]

The pregnancy rate improvement is most robust in men with clinical (palpable) varicoceles and at least one abnormal semen parameter. Treatment of subclinical varicoceles (ultrasound-only findings without physical examination findings) does not consistently improve fertility outcomes and is not generally recommended.

When to Treat

Clinical guidelines from the American Urological Association, European Association of Urology, and American Society for Reproductive Medicine recommend varicocele treatment when:

1. The varicocele is clinically palpable (Grade I–III)
2. The couple has documented infertility (12 months without conception, or 6 months if the female partner is over 35)
3. Semen analysis shows at least one abnormal parameter
4. No identifiable female factor requiring immediate IVF

For men without fertility goals, treatment is indicated when:

• Varicocele is associated with symptomatic testicular discomfort
• Low testosterone with clinical varicocele in a man who would otherwise be a TRT candidate
• Adolescent with documented progressive testicular volume loss

Treatment Options

Surgical Varicocelectomy

The gold standard is microsurgical subinguinal varicocelectomy — performed under operating microscope magnification at the subinguinal level. This approach has the lowest recurrence rate (<1%) and lowest complication rate (hydrocele formation <1%) compared to other surgical approaches.

Laparoscopic varicocelectomy and conventional (non-microsurgical) approaches have higher recurrence and complication rates and are not preferred by most andrologists.

Percutaneous Embolization

An interventional radiology procedure that occludes the varicocele without surgical incision. Less invasive than surgery, with a somewhat higher recurrence rate (5–10% vs. <1% for microsurgery). Appropriate for men who prefer non-surgical approaches or have had failed surgical repair.

Recovery

• Return to light activity: 2–3 days
• Avoid heavy lifting and sexual activity: 2 weeks
• Semen analysis: Repeated at 3 and 6 months post-repair
• Testosterone testing: 6 months post-repair

What Varicocele Treatment Does Not Fix

Varicocele repair improves the testicular environment but does not reverse:

• Pre-existing genetic causes of infertility (chromosomal, Y-chromosome microdeletion)
• Azoospermia from complete spermatogenic failure (though repair can occasionally restore some production in men with non-obstructive azoospermia) [^cayan2009]
• Female partner infertility factors
• Long-standing Leydig cell damage in older men

Bottom Line

Varicocele is the most common correctable cause of male infertility and a significant contributor to testosterone deficiency in affected men. The mechanism — scrotal hyperthermia damaging Leydig cells and spermatogenesis — is well understood. Microsurgical repair reliably improves semen parameters and raises testosterone in the majority of hypogonadal men with clinical varicocele. Men with low testosterone and a palpable varicocele should be evaluated for repair before considering testosterone replacement therapy.