Varicocele and Male Fertility: Diagnosis, Treatment, and Impact on Testosterone

Your urologist told you that you have a varicocele — a collection of enlarged veins in your scrotum that feels like a "bag of worms." You may have been told it's nothing to worry about, or you may have been told it needs surgery. You may have discovered it during a fertility workup, or noticed it yourself as a dull ache that gets worse after standing all day.

Varicoceles are the most common identifiable cause of male infertility — and one of the most treatable. They also affect testosterone production in ways that are underappreciated. Here's what you need to know.

What a Varicocele Is

A varicocele is an abnormal dilation of the pampiniform venous plexus — the network of veins that drains blood from the testes. Think of it like varicose veins, but in your scrotum instead of your legs.

They occur in approximately 15% of all men, but are found in 35-40% of men with primary infertility and up to 80% of men with secondary infertility (men who previously fathered children but are now having difficulty).

Why the left side? About 85-90% of varicoceles are on the left side. This is due to anatomy — the left testicular vein drains into the left renal vein at a right angle (creating higher venous pressure), while the right testicular vein drains directly into the inferior vena cava at an acute angle (lower pressure). The longer course and perpendicular insertion of the left testicular vein makes it more susceptible to venous reflux and dilation.

Bilateral varicoceles occur in about 40% of cases, though the left side is usually more prominent.

How Varicoceles Damage Fertility and Testosterone

The exact mechanisms are debated, but several pathways contribute:

Testicular hyperthermia. This is the most accepted theory. The pampiniform plexus normally functions as a heat exchanger — cooling arterial blood flowing into the testes by transferring heat to venous blood flowing out. When the veins are dilated, this countercurrent heat exchange fails. Testicular temperature rises by 1-2 degrees Celsius, which is enough to impair spermatogenesis and Leydig cell function. Sperm production requires temperatures 2-4 degrees below core body temperature — there's very little margin.

Venous reflux of adrenal metabolites. The left testicular vein connects to the left renal vein, which also receives drainage from the left adrenal vein. Retrograde flow may expose the testes to adrenal metabolites (catecholamines, cortisol, prostaglandins) that are toxic to spermatogenesis.

Hypoxia and oxidative stress. Venous stasis leads to reduced oxygen delivery and accumulation of reactive oxygen species (ROS). Oxidative stress damages sperm DNA, membranes, and motility.

Hormonal disruption. Varicoceles can impair Leydig cell function, reducing testosterone production. Studies show men with varicoceles have lower testosterone levels on average than men without, even when sperm parameters are not yet affected. Testosterone production may be the earliest casualty of varicocele-related damage.

Diagnosis

Clinical Examination

Varicoceles are graded on physical exam:

• Grade I (subclinical): Not palpable or visible at rest. Detectable only with Valsalva maneuver (bearing down) or ultrasound.
• Grade II: Palpable at rest but not visible
• Grade III: Visible through the scrotal skin without palpation

The exam should be performed with the patient standing (varicoceles decompress when lying down) and with/without Valsalva.

Imaging

Scrotal ultrasound with Doppler is the gold standard. It confirms the diagnosis, measures vein diameter (>3mm is diagnostic), and demonstrates venous reflux with Valsalva. It also evaluates testicular size — asymmetry (the left testis being smaller) suggests the varicocele has impaired testicular growth or caused atrophy.

When Treatment Is Recommended

Not all varicoceles need treatment. Current guidelines recommend treatment when ALL of the following are present:

1. The varicocele is palpable (Grade II or III)
2. The couple has infertility (inability to conceive after 12 months of unprotected intercourse)
3. The female partner has normal fertility (or correctable female factors)
4. Semen analysis is abnormal (low count, poor motility, or abnormal morphology)

Treatment is also considered when:

• An adolescent has a varicocele with ipsilateral (same-side) testicular atrophy — early repair may preserve future fertility
• A man has a varicocele with low testosterone and symptoms of hypogonadism — repair may improve testosterone production
• Pain is the primary complaint — varicocele repair can relieve chronic scrotal pain in most cases

Treatment is NOT recommended for:

• Subclinical (non-palpable) varicoceles
• Men with normal semen parameters who are not seeking fertility
• Asymptomatic varicoceles without fertility concerns

Treatment Options

Surgical Repair

Microsurgical subinguinal varicocelectomy — The gold standard. Performed through a small incision below the inguinal ligament. Using an operating microscope, the surgeon identifies and ligates the dilated veins while preserving the testicular artery, lymphatics, and vas deferens.

• Success rate (semen improvement): 60-70%
• Pregnancy rate after repair: 30-50%
• Recurrence rate: 1-2% (lowest of any approach)
• Hydrocele formation (complication): <1% with microsurgical technique

Laparoscopic varicocelectomy — Less commonly performed. Higher recurrence rate than microsurgical approach.

Open inguinal or retroperitoneal approaches — Older techniques with higher recurrence and complication rates.

Percutaneous Embolization

An interventional radiology procedure performed through a catheter (usually inserted via the neck or groin vein). A coil or sclerosing agent is used to block the dilated testicular vein from the inside.

• Success rate: Similar to surgical repair for semen improvement
• Advantages: No incision, faster recovery (1-2 days vs. 1-2 weeks), no general anesthesia
• Disadvantages: Slightly higher technical failure rate, radiation exposure, higher recurrence rate (5-10%)

Expected Outcomes After Treatment

Semen parameters: Improvement typically occurs within 3-6 months (one full spermatogenesis cycle is approximately 74 days). Most studies show improvement in sperm concentration, motility, and morphology.

Testosterone levels: Multiple studies demonstrate testosterone increases of 50-150 ng/dL after varicocelectomy. A meta-analysis found a mean increase of approximately 100 ng/dL. This is clinically significant, particularly for men with borderline testosterone levels.

Spontaneous pregnancy: Meta-analyses report spontaneous pregnancy rates of 30-50% within 1-2 years of repair, compared to 15-20% without repair.

Time to improvement:

• Testosterone improvement: 3-6 months
• Semen improvement: 3-12 months
• Peak fertility benefit: 6-18 months after repair

Varicocele and Testosterone (Without Fertility Concerns)

Even outside the fertility context, varicoceles affect testosterone. Men with varicoceles have lower mean testosterone levels than matched controls. Repair has been shown to increase testosterone — which means for men with borderline low testosterone and a palpable varicocele, surgical repair may improve testosterone without TRT.

This is particularly relevant because:

• TRT suppresses spermatogenesis (counterproductive if fertility is desired later)
• Varicocelectomy addresses the cause of the low T rather than supplementing around it
• The testosterone increase after repair, while modest, may be sufficient to resolve symptoms in borderline cases

At CORAL, Dr. Kim includes varicocele assessment in the evaluation of men with low testosterone, particularly when the cause isn't immediately obvious. While surgical management requires a urology referral, the diagnostic evaluation and testosterone management can begin via telehealth.

Living with a Varicocele

If your varicocele doesn't meet treatment criteria (small, asymptomatic, normal fertility):

• Annual semen analysis if you're planning future fertility
• Periodic testosterone monitoring to catch decline early
• Supportive underwear — may reduce discomfort from gravitational pull
• Awareness — if symptoms develop or fertility becomes a concern, reassess treatment

Getting Evaluated

If you've been told you have a varicocele — or if you're experiencing fertility difficulties, scrotal pain, or low testosterone — understanding whether the varicocele is contributing is the first step.

[Start a visit at coral.clinic/start](https://coral.clinic/start). Dr. Kim can order the appropriate labs (semen analysis, testosterone panel), coordinate imaging, and determine whether your varicocele needs treatment or monitoring — and refer to urology when surgical intervention is indicated.