Does Varicocele Affect Testosterone Levels?

Varicocele, the enlargement of veins within the scrotum, is associated with lower testosterone levels in a meaningful number of affected men. Large controlled studies show that men with varicocele have measurably lower average testosterone than men without the condition, and the gap appears to widen with age and disease severity. The relationship is not universal, though, and how much testosterone drops, whether surgical repair reverses it, and who benefits most are all questions with more nuanced answers than a simple yes or no.

How Varicocele Drives Testosterone Down

Testosterone production in the testes depends heavily on temperature. The scrotum is designed to keep the testes a few degrees cooler than the rest of the body, partly through a heat-exchange system between outgoing venous blood and incoming arterial blood. A varicocele disrupts that cooling. When veins in the pampiniform plexus become dilated and blood pools instead of draining efficiently, scrotal temperature rises. That extra warmth directly impairs the Leydig cells, which are the cells responsible for making testosterone.

The damage is enzymatic. Heat specifically inhibits an enzyme called C-17,20-lyase, which is needed to convert hormone precursors into testosterone. When that enzyme is suppressed, levels of intermediate hormones like 17-OH-progesterone rise while testosterone output falls.¹ Beyond enzyme inhibition, animal studies have shown that varicocele increases the rate of Leydig cell death through apoptosis and reduces the expression of a key protein (StAR) that Leydig cells need to begin making testosterone in the first place.² In rat models, the number of Leydig cells per square millimeter progressively declined over months of induced varicocele, and testosterone dropped alongside them.³

Oxidative stress also plays a role. Varicocele is associated with increased production of reactive oxygen species in the testes, which can damage cells and reduce overall testicular function, including both sperm production and hormone output.⁴ The combination of heat stress, enzyme suppression, and oxidative damage creates several pathways through which varicocele can lower testosterone.

How Much Lower Is Testosterone in Men with Varicocele?

The difference is real, if not always dramatic. A large retrospective study comparing men with varicocele to men without found average testosterone levels of about 416 ng/dL in the varicocele group versus 469 ng/dL in the comparison group. That gap persisted across age groups.⁵ A prospective controlled study reported even starker numbers: men with varicocele had baseline testosterone around 340 to 400 ng/dL, while men without varicocele averaged roughly 505 ng/dL.⁶

To put that in perspective, many clinicians consider testosterone below 300 ng/dL as the threshold for deficiency. A man whose baseline testosterone would otherwise sit comfortably in the normal range might find that a varicocele pushes him closer to or below that cutoff. That does not mean every man with a varicocele will become clinically hypogonadal, but it does mean the condition shifts the curve downward for many.

Not Every Man with Varicocele Has Low Testosterone

This is a point that deserves its own spotlight, because it is easy to read the studies above and assume varicocele always means hormonal trouble. In fact, a majority of men with varicocele have testosterone levels that fall within the normal laboratory range. One evaluation of varicocele patients found that in most cases, both testosterone and FSH levels were normal.⁷ The averages are lower in large group comparisons, but averages mask a wide spread of individual outcomes. Some men with a large, clinically obvious varicocele maintain robust testosterone levels, while others with a smaller one may be more affected.

The reasons for this variability are not entirely clear. Body composition, genetic differences in Leydig cell resilience, the degree to which the heat-exchange mechanism is compromised in a particular man’s anatomy, and whether the varicocele is unilateral or bilateral all likely play roles. The takeaway is that a varicocele diagnosis alone does not predict your testosterone status. Blood work is what tells you whether your levels are actually affected.

Does Varicocele Grade or Severity Matter?

Varicoceles are clinically graded from I (detectable only with a Valsalva maneuver) to III (visible through the skin without any special maneuver). You might expect that bigger varicoceles cause bigger hormonal problems, and some evidence supports that expectation, though it is not entirely straightforward.

A large cohort study found that testosterone levels and body mass index were both significantly associated with varicocele grade. Interestingly, the study observed higher testosterone levels in men with higher-grade varicoceles, which the authors attributed to the complex interplay between BMI and varicocele detectability rather than to a protective effect of larger varicoceles.⁸ Leaner men are more likely to have palpable, higher-grade varicoceles diagnosed, and leaner men also tend to have higher testosterone. That confounding factor makes it tricky to disentangle grade from hormonal impact in cross-sectional data.

Bilateral varicoceles and high-grade varicoceles do appear to be associated with lower testosterone and smaller testicular size, particularly in older men.⁹ The picture that emerges is that severity matters, but it is one factor among many, and clinical grade alone is a rough predictor of hormonal consequences.

A Progressive Problem That Worsens with Time

One of the more concerning aspects of varicocele is that the damage may not be static. There is a general understanding in urology that men with palpable varicoceles are at risk for a progressive decline in both fertility and testosterone over time.¹⁰ The animal data support this: in the rat study mentioned earlier, testosterone did not drop significantly until eight months of induced varicocele, suggesting a gradual accumulation of damage rather than an immediate hormonal crash.³

This has real implications for younger men. Varicocele is common, affecting roughly 15 percent of men in the general population, and it is often diagnosed during fertility workups or incidentally during physical exams. A 25-year-old with a varicocele and normal testosterone might not feel any urgency about the condition. But if the damage accumulates, that same man at 40 or 50 could be dealing with low testosterone and the symptoms that come with it: fatigue, reduced libido, loss of muscle mass, and mood changes. Cross-sectional studies of men over 40 confirm that varicocele presence is associated with lower testosterone, smaller testes, and softer testicular consistency in older age groups.⁹

Can Surgical Repair Raise Testosterone?

For men whose testosterone has dropped below normal, varicocele repair (varicocelectomy) is one of the few interventions that may address the underlying cause rather than just supplementing the hormone externally. Reviews of the clinical literature conclude that repair can increase testosterone in men who have both a palpable varicocele and documented testosterone deficiency.¹¹

The numbers from individual studies are encouraging for men who start with low levels. In a prospective trial of men undergoing varicocelectomy, those who began with testosterone below 300 ng/dL saw an average increase from roughly 219 to 358 ng/dL at six months after surgery. That is a jump from clearly deficient to within the normal range for most laboratories.¹² Similar improvements have been reported whether the repair is done surgically or through embolization, a less invasive procedure in which the dilated veins are blocked from the inside. One study found that embolization of the internal spermatic vein increased both total and free testosterone concentrations, regardless of varicocele size.¹³

After successful repair, you’d expect the body to recognize the increased testosterone output and dial back its own signals. That is exactly what one study showed: LH levels decreased after varicocelectomy, which makes physiological sense. When the testes produce more testosterone on their own, the brain’s pituitary gland no longer needs to send as much LH to stimulate production.¹⁴

When Repair Does Not Change Testosterone

The optimistic post-surgery data has an important caveat. Not every study has found that varicocelectomy raises testosterone. One study specifically measuring both blood testosterone and testosterone levels within the testicular tissue itself found no change in either after microsurgical repair, even though semen quality improved. The authors suggested that whatever mechanism varicocelectomy uses to improve sperm production might be independent of testosterone changes.¹⁵

This is not necessarily a contradiction of the other studies so much as a reflection of who was being studied. The biggest testosterone gains after repair consistently show up in men who had low testosterone to begin with. Men whose testosterone was already in the normal range before surgery tend to see little to no change. This makes intuitive sense: if the Leydig cells were not severely damaged, there is not much ground to recover. The clinical implication is that varicocelectomy is most likely to raise testosterone in men who actually need it raised, which is also the group for whom it matters most.

It also means that a man with a varicocele and normal testosterone should not expect surgery to give him a hormonal boost. The repair is not a testosterone-enhancement procedure. It is a treatment for a specific dysfunction, and its hormonal benefits track with the severity of that dysfunction.

Older Men Benefit Too

There is a lingering assumption in some clinical circles that varicocele repair is mainly a younger man’s procedure, aimed at improving fertility. But the testosterone question broadens the relevance. A study specifically looking at older men undergoing microsurgical varicocelectomy found that improvements in semen quality and testosterone were comparable to those seen in younger men.¹⁰ Age alone did not blunt the hormonal response to repair.

This matters because older men are more likely to be symptomatic from low testosterone and more likely to be offered testosterone replacement therapy (TRT) as the default treatment. TRT works but comes with trade-offs: it shuts down sperm production, requires ongoing treatment, and has side effects of its own. For an older man with a palpable varicocele and low testosterone, repair offers a potential alternative that treats the root cause. That said, it is not always offered. Many men are placed on TRT without anyone checking for varicocele, because the association between varicocele and testosterone is less widely appreciated than the association between varicocele and infertility.

Sexual Function Improvements Beyond the Lab Numbers

Testosterone levels are a lab value. What men actually want to know is whether they will feel any different. One study directly addressed this by measuring patient-reported sexual function before and after microsurgical varicocelectomy. The findings showed improvements in both erectile and ejaculatory function after surgery, alongside the expected rise in testosterone.¹⁶ The authors noted that patients can be counseled that varicocelectomy has the potential to improve sexual function, not just laboratory numbers.

This is an underappreciated angle. Many men with varicoceles are seen in fertility clinics, where the conversation revolves around sperm counts and motility. The hormonal and sexual-function dimensions are often secondary in those discussions. For men who are not trying to conceive but are experiencing symptoms consistent with low testosterone, the sexual-function data adds another reason to consider evaluation and possible treatment.

The Hormonal Picture Inside the Veins Themselves

An unusual but informative line of research has looked at hormone levels directly within the spermatic veins rather than in the general bloodstream. In varicocele patients, testosterone concentrations in the spermatic veins were found to be over 13 times higher than in the cubital (arm) veins, while FSH and LH levels showed the opposite pattern: higher in the arm than in the spermatic veins.¹⁷ This steep gradient confirms that the testes are producing testosterone locally, but it also raises questions about whether refluxing blood in varicocele veins might be carrying testosterone-rich blood backward, potentially creating hormonal feedback issues or exposing the testicular environment to abnormal concentrations of its own products.

The intratesticular hormonal environment is harder to study than blood levels drawn from the arm, and most clinical decisions are based on standard blood work. But research into what is happening at the local tissue level helps explain why semen quality and testosterone do not always move in lockstep after varicocele repair. The testes are not a single unified system; they contain specialized microenvironments, and varicocele can affect those environments in ways that standard blood tests do not fully capture.

Varicocele Repair Versus Testosterone Replacement

For a man diagnosed with both varicocele and low testosterone, the practical question becomes: should you fix the varicocele or start testosterone therapy? The two approaches differ in important ways. Testosterone replacement delivers consistent levels and rapid symptom relief, but it suppresses the body’s own hormone production, effectively shutting down sperm production and requiring ongoing use. Varicocele repair, when it works, restores the body’s own testosterone production, preserves or improves fertility, and is a one-time intervention.

Reviews of the literature suggest that microsurgical repair may be preferred when the goal is not just raising testosterone but also preserving testicular function broadly.¹¹ The catch is that not all men respond, and the testosterone gains, while clinically meaningful for men who start with deficient levels, are not as large or as predictable as those achieved with replacement therapy. A man whose testosterone is only mildly below normal and whose varicocele is small may not see enough benefit from repair alone. Conversely, a man with a large palpable varicocele and clearly deficient testosterone is a strong candidate.

No large randomized trial has directly compared varicocelectomy to TRT head-to-head for testosterone outcomes. Most of the evidence comes from before-and-after studies of repair and from observational comparisons. The field has been moving toward recognizing varicocele as a treatable cause of low testosterone, but that awareness has been slower to develop than the recognition of varicocele as a cause of infertility. If you are diagnosed with low testosterone, asking whether a varicocele could be contributing is a reasonable step, especially if you are also interested in preserving fertility.