Conditions
Varicocele
A varicocele is a dilated vein around the testicle. NICE says treatment can be considered when it is felt on examination and semen parameters are reduced.
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Short answer
A varicocele is a dilatation of the veins that drain the testicle, often on the left, sometimes described as a bag of worms when you are standing. Many are found in men who conceive without difficulty. NICE says radiological or surgical treatment can be considered when the varicocele is felt on examination, semen parameters are reduced, and the person is trying to conceive spontaneously. Female fertility factors are part of that decision.
Key takeaways
- A varicocele seen only on ultrasound is not the group NICE’s treatment recommendation is aimed at.
- Evidence of higher pregnancy rates exists for clinically detected varicocele with abnormal semen. Live-birth evidence is thinner and mixed.
- NICE did not find randomised-trial evidence to recommend treating varicocele specifically to improve assisted conception.
- Sudden severe testicular pain is not a varicocele to watch at home. Seek urgent care.
How it is found
The reliable finding for the NICE recommendation is clinical examination, not a scan done because a semen analysis was imperfect. NICE’s committee noted that treating varicoceles which are only detectable on ultrasound would be unnecessary treatment. An examination is also how clinicians look for other scrotal problems, including testicular cancer, after repeated abnormal semen analyses.
What the evidence supports
NICE’s 2026 evidence review found higher pregnancy rates after surgical or radiological treatment, compared with no treatment, in the subgroup with a clinically detected varicocele and abnormal semen analysis. Few studies reported live birth, and those results were mixed. Because of that uncertainty, the recommendation is to consider treatment, not that every varicocele must be repaired. The committee also asked for research comparing radiological, surgical and microsurgical techniques.
The evidence review was about couples trying to conceive without assistance. It is not a SemenBoost instruction to have a repair before IVF.
How care is decided
The decision sits with a urologist or fertility specialist and takes the other partner’s age and fertility into account. If spontaneous conception is not possible because of a female factor, treating the varicocele does not create that chance. Painful varicoceles are a separate urology question from fertility.
Evidence
Moderate evidenceNICE reviewed trials of treating a clinically detected varicocele when semen parameters are reduced and a couple is trying to conceive spontaneously. Pregnancy rates were higher than with no treatment in that subgroup. Live-birth data were sparse and mixed, so this is not rated strong.
Semen parameters
Abnormal semen parameters are part of who was studied. Trials report semen changes, but SemenBoost does not treat a semen-parameter change as proof of a live birth.
Pregnancy and live birth
Pregnancy rates improved in the NICE-reviewed subgroup. Live birth was infrequently reported and the results were mixed. Benefit before assisted conception was not established by randomised trials in that review.
A change in a semen measurement is not the same finding as a pregnancy or a live birth.
Questions
Does a varicocele always cause a low sperm count?
No. Varicoceles are common, including in men with semen analyses inside the reference range. An association is not a rule that every dilated vein explains an abnormal test.
Related
Sources
- Fertility problems: assessment and treatment (NG257) — NICE, 2026
- Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (amended 2024) — American Urological Association, 2024
How this page was prepared
Drafted with automated research assistance and checked against the cited primary sources. A named clinician has not reviewed this page. Medical review is pending. Changes to reference values are not published automatically.