Varicocele — Symptoms, Causes & Treatment | MyMedicPlus

A varicocele is an abnormal dilation and tortuosity of the pampiniform venous plexus within the spermatic cord, analogous to varicose veins in the leg. The pampiniform plexus normally functions as a countercurrent heat exchange system, cooling arterial blood to the testis by 2-4°C below core body temperature — a temperature essential for optimal spermatogenesis (which requires 34-35°C, not the normal 37°C). Varicocele-related venous stasis disrupts this cooling mechanism, impairing sperm production. It is the most common surgically correctable cause of male infertility, present in 15% of the general male population and in 35-40% of men presenting with primary infertility. Left-sided predominance (85-90%) is due to the right-angle drainage of the left testicular vein into the left renal vein, creating greater venous hypertension than the oblique right-sided drainage directly into the IVC.

Incompetent or absent venous valves in the internal spermatic (testicular) vein allow retrograde blood flow and venous hypertension within the pampiniform plexus. Left-sided predominance due to anatomical drainage pattern: left testicular vein drains at a right angle into the left renal vein (versus the right vein draining obliquely into the IVC), creating greater venous pressure in the left plexus. Nutcracker phenomenon (left renal vein compression between the aorta and the superior mesenteric artery) can contribute additional venous hypertension. Isolated right varicocele or rapid-onset varicocele in a man over 45 raises concern for retroperitoneal mass (renal cell carcinoma causing renal vein compression — urgent abdominal imaging required). The elevated venous pressure causes testicular damage through: heat accumulation (venous stasis raises intrascrotal temperature above 35°C, impairing spermatogenesis), accumulation of adrenal metabolites refluxing from the renal vein (cortisol, reactive oxygen species, catecholamines), venous hypoxia, and Leydig cell impairment reducing testosterone production.

Often asymptomatic and discovered incidentally (on fertility evaluation or routine physical examination). Symptomatic: dull scrotal aching or heaviness (worse with prolonged standing or exercise, relieved by lying down — this characteristic postural variation helps distinguish varicocele from other scrotal pathology). Visible or palpable soft, compressible varicosity in the left scrotum when standing — classically described as a 'bag of worms'. Testicular atrophy (hypotrophy — affected testis smaller than the contralateral, assessed by orchidometer or scrotal ultrasound; a volume discrepancy above 20% is clinically significant, particularly in adolescents where progressive growth lag warrants early treatment). Semen abnormalities: oligozoospermia (count below 15 million/mL), asthenozoospermia (reduced motility below 40%), teratozoospermia (abnormal morphology above 96% abnormal forms) — OAT syndrome. In severe bilateral varicocele: symptoms of testosterone deficiency (reduced libido, erectile dysfunction, fatigue) from Leydig cell impairment — testosterone levels may improve following varicocelectomy.

Clinical grading (standing, with Valsalva manoeuvre): Grade I (palpable only during Valsalva — subclinical varicocele is below this), Grade II (palpable without Valsalva), Grade III (visible through scrotal skin without palpation). Scrotal Doppler ultrasound: confirms diagnosis (spermatic cord veins above 2.5 mm diameter, retrograde venous flow on Valsalva); identifies bilateral varicocele (missed on clinical examination alone in approximately 30%); measures testicular volumes bilaterally (critical for monitoring adolescent cases and documenting pre-treatment baseline). Semen analysis: volume, total count, motility, and morphology assessed against WHO 2021 reference ranges (sperm count above 16 million/mL, total motility above 42%, normal morphology above 4% — Kruger strict criteria). Hormonal assessment: FSH, LH, total testosterone, and inhibin B (low inhibin B reflects Sertoli cell dysfunction; low testosterone plus elevated LH indicates Leydig cell impairment). Karyotype (46,XY) and AZF Y-chromosome microdeletion testing if severe oligospermia (below 5 million/mL) or non-obstructive azoospermia. DNA fragmentation index (DFI): above 15-25% associated with poor ART outcomes — varicocelectomy reduces DFI in 60-70% of cases.

Treatment indications: (1) couple with male factor infertility or abnormal semen analysis; (2) adolescent with varicocele + testicular hypotrophy (>20% volume difference); (3) symptomatic pain unresponsive to NSAIDs. Surgical: microsurgical subinguinal varicocelectomy (gold standard) — lowest recurrence rate (<1%), lowest hydrocele formation rate (<1%); preserves testicular arteries and lymphatics. Radiological: percutaneous retrograde embolization (local anesthesia, outpatient, no incision); comparable efficacy but higher recurrence (5-10%). Semen parameters improve in 60-70% at 6-12 months post-surgery; spontaneous pregnancy rate increases by 30-40%. Regular monitoring of treatment response, early detection of side effects, and ongoing assessment of disease progression are essential components of optimising patient outcomes over the long term. Treatment plans should be proactively reviewed and appropriately adjusted based on clinical response, patient-reported tolerability, changing patient circumstances, and continuously evolving evidence-based clinical guidelines. Meaningful shared decision-making between patients and their healthcare team, incorporating patient values and treatment preferences, consistently improves both treatment adherence and long-term outcomes.

Progressive testicular damage from increased testicular temperature (venous stasis raises intrascrotal temperature by 1-2°C above optimal — spermatogenesis requires 34-35°C, and even a 1°C elevation significantly reduces sperm output, motility, and DNA integrity), oxidative stress (elevated reactive oxygen species generated by venous hypoxia damage sperm cell membranes and DNA — sperm DNA fragmentation index (DFI) is elevated in 60-70% of men with clinical varicocele), and venous accumulation of adrenal metabolites refluxing from the renal vein (cortisol, catecholamines) causing Leydig cell dysfunction with subnormal testosterone production. Worsening semen parameters (progressive oligoasthenoteratozoospermia — OAT syndrome) and declining sperm DNA integrity occur progressively over time without treatment — the damage is cumulative and may become irreversible with long-standing untreated high-grade varicocele. In adolescents, untreated high-grade varicocele causes progressive ipsilateral testicular growth arrest; catch-up growth occurs in approximately 80% after varicocelectomy when performed during adolescence, underlining the importance of early treatment referral. Post-operative complications: hydrocele formation (the most common surgical complication — 10% with open technique from inadvertent lymphatic ligation, below 1% with microsurgical subinguinal approach using optical magnification to identify and preserve lymphatics); wound haematoma; testicular artery injury (rare with microsurgery — can lead to testicular atrophy and hormonal impairment — emphasising why microsurgical expertise is essential); and recurrence (below 1% microsurgical vs. 5-10% with embolisation).

No modifiable primary prevention — varicocele development arises from structural anatomical predisposition (incompetent or absent venous valves in the internal spermatic vein; left-sided predominance from the perpendicular entry of the left testicular vein into the left renal vein) and is not preventable. Regular testicular self-examination from puberty allows early detection of varicocele and testicular abnormalities; any new or worsening scrotal fullness or heaviness warrants urological assessment. Antioxidant supplementation (vitamin C 1000 mg, vitamin E 400 IU, coenzyme Q10 200 mg, zinc 15 mg, selenium 200 mcg daily) may improve semen quality by reducing varicocele-related oxidative stress — multiple small randomised trials show consistent improvements in sperm concentration and motility; adjunctive role only, not a substitute for surgical repair in men meeting treatment criteria. Scrotal supportive underwear and avoiding prolonged standing reduce symptomatic scrotal discomfort without addressing the underlying pathology. Surgical treatment should not be unnecessarily delayed in young men with progressive semen parameter decline, clinical varicocele on examination, or testicular volume discrepancy above 20% — testicular damage from varicocele is cumulative, progressive, and potentially irreversible if left untreated for many years; varicocelectomy outcomes are substantially better when performed early, particularly during adolescence when catch-up testicular growth can be achieved.

See your GP for assessment if: you notice a persistent painless swelling or lump in the scrotum that feels like a 'bag of worms' — a varicocele does not usually require urgent referral but should be examined and, if confirmed, semen analysis requested; you are in a couple that has been trying to conceive for 12 months without success (or 6 months if you or your partner are over 35) — all men in this situation should have semen analysis, and if varicocele is found it should be investigated; mild to moderate scrotal ache or heaviness, especially after prolonged standing or exercise — varicocele is a common cause of chronic scrotal pain, and diagnosis guides treatment. Seek same-day or urgent medical assessment for: acute severe testicular pain with rapid scrotal swelling — testicular torsion (twisting of the testis cutting off its blood supply) is a surgical emergency requiring exploration within 4-6 hours; do not assume sudden severe testicular pain is varicocele-related; a new firm testicular mass — must urgently exclude testicular cancer (serum AFP, HCG, LDH, and scrotal ultrasound); a varicocele that develops suddenly in an older man (above 45) or only on the right side — a right-sided varicocele or sudden left-sided varicocele can indicate retroperitoneal pathology (renal tumour with renal vein compression) — requires urgent abdominal imaging.