A varicocele is an enlargement of the veins within the loose bag of skin that holds the testicles (the scrotum), similar to a varicose vein in the leg. This condition affects the pampiniform plexus of veins and is a common cause of low sperm production and decreased sperm quality, which may lead to male infertility. What exactly is a varicocele and how does it affect the body? A varicocele occurs when the valves inside the veins along the spermatic cord do not work properly. This prevents blood from flowing efficiently, causing it to pool and enlarge the veins. This condition primarily affects the male reproductive system. Because the pooled blood increases the temperature within the scrotum, it can negatively impact sperm production and testosterone levels. While many men with a varicocele experience no symptoms, others report a dull, aching pain or a feeling of heaviness in the scrotum, particularly after standing or physical exertion for long periods. How common is this condition and who does it affect? Varicocele is surprisingly common, affecting approximately 15% to 20% of the general male population. It is most frequently diagnosed in adolescents and young adults between the ages of 15 and 25. Because the condition develops slowly, it is rarely seen in boys younger than 10. While there is no specific geographic predisposition, it is the most frequent cause of reversible male infertility, identified in about 40% of men undergoing evaluation for primary infertility. How are varicoceles classified? Clinical classification of a varicocele is typically based on the size and palpability of the veins during a physical examination: Subclinical: Cannot be felt or seen, but is detectable via imaging tests like a scrotal ultrasound. Grade 1: Palpable only when the patient performs a Valsalva maneuver (a breathing technique that increases abdominal pressure). Grade 2: Palpable while standing without the need for a Valsalva maneuver. Grade 3: Visible through the skin of the scrotum upon simple inspection. How does a varicocele differ from other scrotal conditions? It is important to differentiate a varicocele from other causes of scrotal swelling. Unlike a hydrocele (a fluid-filled sac) or a spermatocele (a benign cyst), a varicocele is specifically vascular in nature. Physicians often describe the sensation of the enlarged veins as feeling like a "bag of worms." If you notice sudden, painful swelling on only the right side, a physician must rule out other causes, as a right-sided varicocele can sometimes be a sign of an underlying obstruction in the abdomen, such as a kidney tumor. Next steps Consult a urologist for a physical examination and, if necessary, a scrotal ultrasound to confirm the diagnosis. If you are concerned about fertility, request a semen analysis to assess sperm count and motility. Connect with others navigating this condition by joining the community at DiseaseMaps.org, where members share their personal experiences and management strategies. Monitor for any changes in scrotal size or pain levels and report them to your healthcare provider promptly. Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition. References NIH Genetic and Rare Diseases Information Center (GARD): Varicocele overview. American Urological Association (AUA): Guidelines on the management of infertility in men. Orphanet: Information on male reproductive system disorders. PubMed/NCBI: Clinical literature on the pathophysiology of pampiniform plexus dilation.

Short answer · Medically reviewed summary · Last updated: 2026-04-07

A varicocele is an enlargement of the veins within the loose bag of skin that holds the testicles (the scrotum), similar to a varicose vein in the leg. This condition affects the pampiniform plexus of veins and is a common cause of low sperm production and decreased sperm quality, which may lead to male infertility. What exactly is a varicocele and how does it affect the body? A varicocele occurs when the valves inside the veins along the spermatic cord do not work properly.

What is Varicocele

Name: What is Varicocele
Creator: DiseaseMaps Editorial Team
Published: 2015-07-02UTC01:47:02.0000000

What is Varicocele? Plain-language, medically reviewed definition plus the lived reality told by patients.

A varicocele is an enlargement of the veins within the loose bag of skin that holds the testicles (the scrotum), similar to a varicose vein in the leg. This condition affects the pampiniform plexus of veins and is a common cause of low sperm production and decreased sperm quality, which may lead to male infertility.

What exactly is a varicocele and how does it affect the body?

A varicocele occurs when the valves inside the veins along the spermatic cord do not work properly. This prevents blood from flowing efficiently, causing it to pool and enlarge the veins. This condition primarily affects the male reproductive system. Because the pooled blood increases the temperature within the scrotum, it can negatively impact sperm production and testosterone levels. While many men with a varicocele experience no symptoms, others report a dull, aching pain or a feeling of heaviness in the scrotum, particularly after standing or physical exertion for long periods.

How common is this condition and who does it affect?

Varicocele is surprisingly common, affecting approximately 15% to 20% of the general male population. It is most frequently diagnosed in adolescents and young adults between the ages of 15 and 25. Because the condition develops slowly, it is rarely seen in boys younger than 10. While there is no specific geographic predisposition, it is the most frequent cause of reversible male infertility, identified in about 40% of men undergoing evaluation for primary infertility.

How are varicoceles classified?

Clinical classification of a varicocele is typically based on the size and palpability of the veins during a physical examination:

Subclinical: Cannot be felt or seen, but is detectable via imaging tests like a scrotal ultrasound.

Grade 1: Palpable only when the patient performs a Valsalva maneuver (a breathing technique that increases abdominal pressure).

Grade 2: Palpable while standing without the need for a Valsalva maneuver.

Grade 3: Visible through the skin of the scrotum upon simple inspection.

How does a varicocele differ from other scrotal conditions?

It is important to differentiate a varicocele from other causes of scrotal swelling. Unlike a hydrocele (a fluid-filled sac) or a spermatocele (a benign cyst), a varicocele is specifically vascular in nature. Physicians often describe the sensation of the enlarged veins as feeling like a "bag of worms." If you notice sudden, painful swelling on only the right side, a physician must rule out other causes, as a right-sided varicocele can sometimes be a sign of an underlying obstruction in the abdomen, such as a kidney tumor.

Next steps

Consult a urologist for a physical examination and, if necessary, a scrotal ultrasound to confirm the diagnosis.

If you are concerned about fertility, request a semen analysis to assess sperm count and motility.

Connect with others navigating this condition by joining the community at DiseaseMaps.org, where members share their personal experiences and management strategies.

Monitor for any changes in scrotal size or pain levels and report them to your healthcare provider promptly.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.