Varicocele: The Internal Ball Cooker

The ugly step-brother to varicose veins, varicoceles are dialated viens in the scrotum that can cause pain, infertility & low T. Surprisingly common, they impact 15% of all men and can be corrected surgically.


One of the leading causes of male infertility is an internal plumbing condition called a varicocele. Varicocele refers to an enlarged bundle of veins (the pampiniform venous plexus) leading from the testicles into the abdomen due to reduced blood flow. Believe it or not, a primary function of these veins is to reduce the local scrotum temperature by pumping the blood out of the area. These swollen veins therefore increase the temperature of the testicles (aka cook the balls), and lead to reduced sperm quality. What’s going on, and what can you do about it? Read on…

What causes varicoceles?

Varicoceles are the uglier cousins of varicose veins – the enlarged blue veins commonly found in legs in people with poor blood circulation. When the veins do not pump blood as well as they need to, the veins will dilate. Interestingly, while varicoceles can occur to either the left or right side plexus (connected to the left and right testicles), most occur on the left side.

The exact cause of varicoceles remains unknown, although there are 3 leading theories:

Theory 1: Routing of pipes

Your pipes are not symmetric. The left-testicular vein empties into the renal vein at a 90 degree angle, while the right-testicular vein empties into the larger inferior vena cava at a reduced angle. Thus there is a greater likelihood of higher pressure on the left vein, leading to much more common left-side varicoceles.

Theory 2: Poor valving

These veins have one-way valves in them that help prevent back-flow of blood. After all, they’re trying to pump blood against gravity. If the valves do not work properly (or are not present at all), there is a much greater likelihood that the veins will dilate from excess blood.

Theory 3: The “Nutcracker Effect”

This theory proposes that the testicular veins become partially obstructed when the left renal vein gets compressed between the aorta and superior mesenteric artery.

In reality, the root cause is probably a combination of these factors.

How common are they?

Unfortunately, varicocele is a pretty common condition. They are found in 15% of all men, 35% of infertile men who have never fathered a child, and 81% of men who were once fertile but are now infertile (secondary fertility). The condition seems to arise in most men during puberty; varicoceles rarely develop in men over the age of 40.

Can I tell if I have one?

Varicoceles are progressive legions, meaning that they start small and grow over time. Very small varicoceles usually don’t present symptoms other than occasionally impacting sperm quality. In the case that you have an abnormal semen analysis, the doctor may perform an ultrasound of the scrotum to look for small varicoceles or inflammation of the epididymus. While performing the ultrasound, they will measure the diameter of the plexus of veins. Technically, a varicocele refers to a plexus that is greater than 2mm in diameter (normal diameter is 0.5mm – 1.5mm).

As the varicocele grows over time it can be identified by examining the testicle. Doctors will feel for an enlarged bundle of veins along the spermatic cord. If the varicocele is large enough, you may be able to feel it yourself as they can make the scrotum feel like a “sack of worms.” Even larger varicoceles are visible and you can see the bluish color of the vein through the thin skin of the scrotum.

Some men experience other symptoms associated with the varicocele. It can cause the testicles to hang lower than usual, feel heavy (particularly after long periods of standing) or even cause a dull pain. If you are experiencing any of these symptoms and are thinking about having children, it is a good idea to go in and get checked out.

How varicoceles impact fertility

Many studies have linked poor sperm quality to varicoceles in subfertile men. The effects include diminished sperm count, motility, and morphology. Some researchers have also linked varicoceles to reduced sperm function, meaning that despite normal count, motility, and morphology, the sperm is still unable to fertilize an egg. However, the exact physiological explanation of why varicoceles inhibit male fertility remains partly controversial. There are several leading theories:

1. Hyperthermia

The veins help keep the scrotum a few degrees below normal body temperature, which is essential for proper sperm production. If the vein function is impaired, the heat exchanger loses its efficiency and scrotal temperature can increase. (This is why we call varicoceles the internal ball cooker).

2. Venous pressure

Varicoceles may cause the blood pressure in the veins to increase. The increased pressure may inhibit metabolic processes within the testicles, and also reduce vascular drainage from the area which can lead to an accumulation of toxins in the area.

3. Hormone imbalance

Related: Hypogonadism

Many studies have linked varicoceles to lower levels of testosterone. This finding suggests that the condition may affect of the Leydig cells in the testicles, which are responsible for testosterone production.

4. Reactive oxygen species

The production of reactive oxygen species (ROS) is critical to proper sperm function. However, an abundance of ROS can impair sperm motility and morphology. High ROS levels in semen have been found in men with varicoceles.

What can you do about it?

Not all varicocele need treatment. If you have no plans to have kids (or more kids), if you’re not experiencing pain, if you have no trouble conceiving, or even if you do, if your semen parameters (count, motility, etc.) are normal, you and your doctor may decide to put off or even skip treatment. However, for guys still planning to start or grow a family, whether through intercourse, artificial insemination, or IVF, it’s a good idea to examine treatment options if your semen parameters are abnormal and you’re having difficulty conceiving.


This is performed by a urologist to repair (by obstructing) the variocele, and it’s the most common treatment. With a successful repair, most men will see an improvement (after 4-6 months) in count, motility, and morphology, and a decrease in sperm DNA fragmentation.

The procedure itself is usually a minimally invasive, microscopic surgery to cut and remove the portions of veins causing the problem. In most cases, this is an outpatient procedure with a few days off of work. Sometimes, depending on the size, number, and position of variocele, this procedure is performed more invasively, either through laparoscopy (laser microscope) or open surgery (larger incision). Laparoscopy, and to a larger extent open surgery, will involve cutting through abdominal muscle, increasing recovery time. Although all variocelectomies tend to improve sperm health, the best outcomes, shortest recovery times, and the fewest complications and recurrences are associated with the microsurgical approach.

The larger the variocele, the more improvement is likely to be shown with surgery. An advantage of variocelectomy is that the surgeon has the vantage point to not only cut the vein currently causing the problem, but also to take care of veins that may cause future problems–without cutting so many veins as to create a new current problem. The most common complication of variocelectomy (all types) is hydrocele (fluid-filled sac around testicle, makes your scrotum swell). Others include injury to the testicular artery and recurrence of varicocele.

Microsurgery can be done with local anesthesia, which reduces general surgical complications; the other methods require general anesthesia (in other words, you’re knocked out) with intubation (a tube down your windpipe to help you breathe, since some of the drugs used in effective anesthesia make it harder to breathe). In some studies, microsurgery was shown to be have fewer complications (hydrocele) and fewer recurrences than the other two methods. Talk with your urologist to understand what options are available to you.

Percutaneous embolization

A possible alternative treatment to surgery is to puncture the dilated vein through the skin to embolize (deliberately block) the varicocele with a chemical that acts a bit like an epoxy for the blood vessels. Coils and balloons can also be used for embolization, which is less invasive than microsurgical ligation (variocelectomy), and can be performed with local anesthesia.

Embolization, often performed by an interventional radiologist, is well-tested in other conditions (such as clots and aneurysms) in other parts of the body. It’s the sort of procedure you’ve may have seen the fictional cardio-thoracic surgeon Dr. Christina Yang perform without need for suction or gauze, but confidently guiding the tiny, flexible needle-and-thread-looking stuff on the ghostly screen.

This method is promising but not well-studied treatment for varicocele repair, though it was first used in this application in 1977. Some types and locations of varicocele may not be suitable for this approach. Also, for embolization in general, recurrence may be an issue.Talk with your doctor to see if this option makes sense for you.


From a distance, this technique looks a lot like embolization. In both, ultrasonic imaging is used to guide a flexible needle into the heart of the variocele (local anesthesia). Except the goal is to dissolve or shrink rather than block (similar results).

This approach is well-tested in varicose veins, the usually leg-located cousin of the testicular varicocele. It has also been in use for varicocele treatment as early as the late 1970s, and is shown to yield improvements in sperm quality. However, if the results for testicular varicocele are similar to the non-reproductive applications of sclerotherapy, it may perform better in the short term than a surgical approach (say, 1 year), but worse in the longer term (more like 5 years).

A main complication of any sclerotherapy is adverse reaction or surrounding tissue damage due to the sclerosing agent used. For this reason, foam preparation of the sclerosing drug is usually chosen for its demonstrated safety (more contained) and efficacy (maximizes surface area and potency in target treatment area). Another potential complication of this procedure is blood clots and swelling of veins due to blood clots. Like embolization, not all varicocele will be accessible by or appropriate for this approach.

Varicocele treatment: a minor controversy

If you put a couple handfuls of fertility experts in a room and asked them to determine, by consensus, the most effective method of varicocele treatment for all individuals, you might want to hide a camera in the room and pop some popcorn. Part of the reason it’s difficult to agree on the best treatment is that the underlying links between varicocele, facets of sperm quality, and ultimately impaired male fertility are not clear. We know varicocele adversely affect male fertility, but studies produce conflicting data when researchers try to correlate successful (by sperm quality and by lack of complications or recurrence) repairs with increased pregnancy outcomes. We know that varicocele treatment improves sperm count and quality outcomes, but is that the whole picture?

Individual differences in size, shape, number, and location of varicocele, as well as differences in the effect the varicocele is having on sperm quality aspects, may impact treatment decisions and outcomes. In addition, some surgeons are more practiced and skilled in particular techniques than others, so be sure to address this with your doctor. As an adult man, when considering any varicocele treatment for the goal of improved fertility, it’s a good idea to sit down with your doctor, your baseline sperm quality results, and any other tests your doctor may have performed in diagnosis and evaluation, and decide which option will be right for the two of you.

Greg Sommer

Greg Sommer

CoFounder & CSO at Trak Fertility. Husband, Father, Men's Health Advocate, and Midwesterner.
Greg Sommer

Author: Greg Sommer


36 thoughts on “Varicocele: The Internal Ball Cooker”

  1. Hi,

    My husband just had a vericocele repaired and a TESE done at the same time. He had 8 large veins fixed but we found no sperm with the TESE. He only has his left testicle because his right was dead and removed at birth. He use to have a very low count but after years it went to 0. His FSH was 19.8. Do you think his sperm could be restored or do you think it’s just testicular failure? Thank you!

    1. If the doc still thinks there’s a shot of finding sperm, its at least worth getting tested in 3 or 6 months. I would test semen, T and FSH. It would give you a sense of if the varicocele was causing the damage or if it was from birth issue. Generally, if they were in doing a TESE they would get an impression of how healthy the tissue was.

      None the less, hard to tell with these things. You may as a couple want to start discussing how you feel about various back up options. Sometimes that is an emotional process that takes time to work through. You may find yourselves on different pages and it is important to hear each other’s perspectives and commit to something that you both can feel good about.

      I’ll be keeping my fingers crossed that the varicocele repair helps improve things…. if you’d like a list of alternative back up options I’m happy to get you started with things I know about.

      XO. Sending big hugs to you both. I know this stuff is hard. You are doing a great job getting educated and advocating for yourselves.

      1. Thank you so much! It’s been a difficult process for us and every step we feel like we meet another bump in the road. I would love a list of backup options. Thank you for taking time to respond.


        1. XO. Sometimes the best things in life do not come in a direct path but by a rocky journey that takes us on hills that are hard to climb, deep waters and difficult paths… still, the journey makes us strong and the destination is all the more breath-taking once you reach it. XOXO.

          Here’s a list of things to talk about / google to learn more about. I’m happy to share what I know if you have follow up questions about any of them:

          Sperm donation (can be used combined with DH or as backup)
          Embryo donation / adoption (frozen embryos from couples who have completed families)
          Foster to adopt
          Pubic adoption
          Private adoption
          International adoption

          **there are several other options if there is suspected female side issues as well

          Wishing you both well. please reach out any time. Happy to be a sounding board or just a shoulder. Xo

  2. Need advice
    Once upon time I had pain in my testicles begin mass right one and left smaller than right some time there is pain when I catch ball there is no the any infection at the moment I met specialist doctor after that sent me laboratory Using ultrasound both testicles then doctor known there is testicle T.b disease so that causes infection blocked tube take sperm and sperm become light or soft water like urine. After that said I have any thing solution your problem icrease solid spermbecause it is low and like water semen said more than two laboratories there are no any semen analysis
    So that I think tube of carried sperm blocked or smaller than normal tube can carry semen
    Or surgery? Is important tube blocked or veins take semen
    Tell me your advice

  3. laboratory passes a tiny hole of the tube
    • injuries or other problems with the tubes that carry sperm
    • , several conditions can change the color and consistency of semen.
    One of the most common causes of watery semen is low sperm count.

    it is more likely to be due to a blockage in a larger vein
    what is it the problem can causes semen low and light

  4. Need advice
    Or surgery is important tube blocked or veins take semen?
    Are you stressed about the idea of surgery?
    Tell me your advice

    1. Let me try to understand better — you had TB and now you do not have any sperm in your semen. Is that correct?

  5. I was diagnosed with varicocele during a physical exam in middle school. I’m now 27. My wife and I want to start trying to get pregnant in 6 months. Should I get a semen analysis now even though we aren’t trying yet? I have no symptoms.

    1. Varicoceles are a risk factor for low sperm count / infertility. It might be worth getting checked. Science doesn’t have a good grasp on the relationship between the two. Some men have large varicoceles that have no impact on fertility and others can have small ones that have a rather large impact on sperm. If you were diagnosed in middle school, guessing that it might be a relatively large one and might be worth exploring impact on fertility. Gives you time to try different things to improve fertility without the stress of trying to conceive.

      Depending on your insurance situation – it may be covered. There are also relatively inexpensive home options that can give you some idea what’s going on.
      I helped co-found one of the start-ups that provide home testing – so I’m partial to that as an option — — they also have a nice app (that I helped develop) that provides a health assessment and provides recommendations to optimize reproductive health. Could be a good tool for planning ahead.

  6. Hi . this is very good form for male fertility due to varicocele . my age 40 years I hv no kids. I feel little pain in my left testicle ball . I softly touch my testicle ball and I feel pain . my sperm count active sprem 20 . in 1996 one time I already take a surgery varicocele that time before surgery my sprem count active 5 active . after surgery my sprem count active 20 . now a days I feel pain in my testicle ball left side . plz tell me what I do.

    1. When was the last time you had a semen analysis?
      Are you trying to conceive now?
      Have you been the to doctor to discuss the new pain?

  7. I had varicocele ever since i hit puberty ,I started feeling a burning pain at 19. I finally got a varicocelectomy I’m 2014, and fathered a child in 2016. The problem is I still have the varicocele, pains, and low muscle mass

    1. Have you been back to the urologist? What did they say? What procedure did they use for varicocelectomy?

  8. Hi
    I’m a 33 year old diagnosed as severe OAT ,i did some investigations like hormonal analysis,chromosomal analysis and scrotal ultrasound
    All is good except the scrotal ultrasound which showed bilateral varicoccele (grade 3 at the left side and 2 at the right side)
    My question is “can such varicoccele lead to SEVERE OAT”?? And am I going to benefit from doing varicoccele surgery?
    My SFA was less than a million total count (0.2 million/ml)
    Thank you


  9. Hi, I did SFA 6 months ago which showed a severe OAT less than a million total count.
    I had an appointment with a urologist who told me that I have a bilateral varicocele grade 3 at left side and 2 at Rt side.and he asked for scrotal doppler ultrasound wich confirmed the diagnosis.
    My question is “does varicocele cause such severe OAT and am i benefit from doing repair?
    Im 33 year old
    My hormonal profile is normal except testosterone level found on the lower boarder of normal range and lower than expected to my age.


    1. Varicocele repair improves semen quality about 60% of the time. Thy can do pretty bad damage. They discovered that varicoceles contribute to poor semen quality when a man with azoospermia (no sperm) had sperm following a varicocele repair. It’s been hard to nail down when it will be effective and when it won’t. It’s a matter of controversy among doctors.

      Given that it is a pretty large varicocele and it’s on both sides, I might consider treatment.

      What did the doc say?

      Do you have other risk factors? Did you do a genetic screen to test for Y deletions?

      1. My urologist said that I have to do the sx and i may improve gradually but he recommends do do IVF during the waiting time assuming no improvement
        I did something called keratotyping which was completely normal

        1. Have you had multiple semen analysis to see if you are improving with your lifestyle changes? Are you thinking to get treatment for the varicocele? I would at least consider actively cooling your balls to see if that helps.

          Glad to hear that genetic stuff all came back normal.

          You might want to use this app to track your semen results and your lifestyle changes

  10. I am a 29 year old man.I had bilateral varicocele. Grade III on my left testicle and Grade I on the right one which i got removed 2 years back but still face issues with erection.
    All i want to know will i be able to have a normal sex life ever again.Will my testicle ever produce the right amount of testosterone>

    1. What is your testosterone reading? Has it improved since procedure? Do you have FSH or LH readings?

      Is erection always a problem or intermittent? Do you have issues with libido as well?

    1. I think it depends on the procedure and the doctor. There are a couple of different options for technique. Have you asked the doctor these questions?

  11. I remember seeing an episode of “Coach” back in the day where the main Character was having fertility/ sperm quality issues and he had to ice his nuts for a while. (Hilarity ensues) … But is there any relevance to this? If I theoretically walked around with an ice pack on my balls for a few months as much as possible, would this/ could this my sperm condition?

    1. Studies have actually shown that men can improve sperm quality by icing… check out our gadgets page. Someone actually invented “icing underwear” for this very purpose.

  12. I linked to this page from the below page that I was initially reading:

    You mention on that page, that there can be some predictive factors which a urologist could provide that could help you make a determination whether or not to do the surgery to remove your varicocele(s). I was told very general statistics about potential improvement by having the varicoceles removed. Are there specific questions that I can ask my urologist that could potentially help me understand whether or not a varicocele has a good likelihood of improving my sperm count? Thank you.

    1. I need to do more research into this. Unfortunately, varicocele repair is a little controversial. Doctors don’t fully understand how and when varicoceles impact fertility and when they don’t. Many urologists that I have talked to have seen very large varicoceles and the semen analysis comes back in the normal range. Other men have tiny varicoceles, that really suppress sperm values and after surgery see great improvements on all values of semen analysis. The first case that connected a varicocele with sperm was a man that had no sperm (azoospermia) and after the varicocele correction was able to produce a good number of sperm.

      Things to think about when considering varicocele repair are:

      1. Are there any issues on her side? Fertility is a team sport and treatment path should consider the state of both partners

      2. How patient are you? Varicocele repair takes about 6 months to see results (they can improve as soon as 3 months and take up to or over a year to fully recover sperm health)

      3. What does your insurance situation look like? Finances are a part of life and a source of deep stress. When combating fertility issues, it is important to keep putting the marriage front and center.

      4. How good is your urologist? You really want to make sure that your urologist is experienced with male fertility issues, microsurgery and varicocele repair. It should be someone who deals with cases like this regularly

      5. Does the varicocele cause discomfort? Varicoceles are progressive — meaning they get larger over time. If you are young and it is causing discomfort now, it may continue to get worse over time

      6. How is your testosterone? Varicoceles can impact testosterone production. If you have symptoms from low T, it may be worth considering a varicocele repair over a lifetime of testosterone therapy

      7. How many kids are you thinking you would like to have? If you are just at the beginning of building your family and think you might want more than one, or don’t know how many kids you’d like, the varicocele repair can give you more options for the future.

      8. How impacted are the sperm parameters? Are they a little low or are they deeply impacted? If you are azoospermic, then varicocele repair is more worth it than if you have counts in the 20s or 30s

      9. How is the rest of your life? Are there things you can do — eat better, sleep better, exercise more, reduce heat, stop smoking etc that could improve semen parameters? If you are in peak condition, then the varicocele is probably a bigger part of the problem than if you have a spare tire or have regular exposures to high heat.

      10. How do you feel? Does medicine make you uncomfortable? Are you stressed about the idea of surgery? Are you stressed about this unresolved issue with your body. At some point, it is a gut call and it can be worth listening to your heart.

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