Testicular atrophy refers to a reduction in the size and volume of one or both testicles. Because the testicles are responsible for producing sperm and testosterone, testicular shrinkage can sometimes be associated with low sperm count, poor sperm production, hormonal problems and male infertility.
While testicular atrophy does not always mean that a man cannot father a child, it should not be ignored, particularly when there is a history of infertility, testicular injury, infection, varicocele or hormonal problems.
At Zemya IVF & Fertility Clinics, evaluation of male fertility includes identifying possible causes of impaired sperm production and developing an appropriate treatment plan based on the individual’s condition.
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What Is Testicular Atrophy?
Testicular atrophy means that the testicles have become smaller than their expected size. It may affect one testicle or both testicles.
The testicles have two important reproductive functions:
- Producing sperm
- Producing testosterone
Therefore, damage or reduced function of the testicles can affect both male reproductive health and hormonal function.
Testicular atrophy can develop because of several underlying conditions, including infections, varicocele, hormonal disorders, testicular injury, undescended testicles, certain genetic conditions and the use of anabolic steroids.
What Causes Testicular Atrophy?
There is no single cause of testicular atrophy. Finding the underlying reason is important because some causes may be treatable.
1. Varicocele
A varicocele is an enlargement of the veins around the testicle. It can affect the testicular environment and is associated with reduced sperm quantity and quality.
2. Testicular Infections
Certain infections can damage the testicular tissue. Orchitis, including orchitis associated with mumps, may affect sperm production and, in some cases, cause lasting testicular damage.
3. Hormonal Imbalances
The brain, pituitary gland and testicles work together to regulate testosterone production and sperm production. Problems involving this hormonal system can contribute to testicular dysfunction and atrophy.
4. Anabolic Steroids and Testosterone Use
Long-term use of anabolic steroids or external testosterone can suppress the body’s natural reproductive hormone signals. This can reduce sperm production and may cause the testicles to shrink.
This is particularly important for men taking testosterone or anabolic steroids for bodybuilding or performance enhancement who are also planning to have children.
5. Testicular Injury
Trauma or injury affecting the testicles can damage the tissue responsible for sperm and hormone production.
6. Undescended Testicles
When one or both testicles do not descend into the scrotum during development, sperm production can be affected and future fertility may be reduced.
7. Genetic Conditions
Certain genetic conditions can affect testicular development and sperm production. Klinefelter syndrome, for example, is associated with impaired sperm production and may present with small testicles.
8. Age, Chronic Illness and Other Factors
Certain long-term health conditions, medications, excessive alcohol consumption and other factors can also affect testicular function and sperm production.
Symptoms of Testicular Atrophy
Some men may notice the change themselves, while others may have no obvious symptoms.
Possible signs include:
- Noticeably smaller testicle or testicles
- Difference in size between the two testicles
- Reduced testicular fullness
- Reduced libido
- Erectile difficulties
- Symptoms associated with low testosterone
- Reduced facial or body hair in cases of significant hormonal deficiency
- Difficulty achieving pregnancy
Importantly, infertility itself may be the first indication of an underlying testicular problem. Male infertility often has no obvious symptoms apart from difficulty causing a pregnancy.
Does Testicular Atrophy Cause Infertility?
It can, depending on its cause and severity.
The testicles are the primary site of sperm production. If testicular tissue has been significantly affected, sperm production may decrease. This can result in:
- Low sperm count
- Poor sperm motility
- Abnormal sperm morphology
- Severe impairment of sperm production
- In some cases, azoospermia, meaning no sperm detected in the ejaculate
However, having a small testicle does not automatically mean infertility. One healthy testicle may be sufficient for testosterone production and sperm production in some men. The actual effect on fertility needs to be determined through appropriate evaluation.
How Is Testicular Atrophy Diagnosed?
A fertility specialist or urologist may begin with a detailed medical history and physical examination.
Depending on the findings, investigations may include:
Semen Analysis
A semen analysis evaluates:
- Sperm concentration
- Sperm motility
- Sperm morphology
- Semen characteristics
Because sperm parameters can vary between samples, repeat testing may sometimes be recommended.
Hormonal Tests
Blood tests may be performed to assess hormones such as:
- Testosterone
- FSH
- LH
- Prolactin
The results can help determine whether impaired sperm production may be related to a testicular or hormonal problem.
Scrotal Ultrasound
A scrotal ultrasound can assess the testicles and surrounding structures and may help identify conditions such as varicocele or other testicular abnormalities.
Genetic Testing
When sperm production is severely impaired, particularly in men with azoospermia or very low sperm concentration and testicular atrophy, genetic evaluation may be recommended in appropriate cases. AUA/ASRM guidance specifically identifies testicular atrophy as one factor that can support consideration of karyotype testing in certain men with primary infertility and severe sperm-production impairment.
Can Testicular Atrophy Be Treated?
Treatment depends entirely on what caused the testicular atrophy.
There is no single medicine that reverses every case of testicular shrinkage.
Treatment may involve:
Treating an Underlying Infection
If an active reproductive-tract infection is identified, appropriate medical treatment may be prescribed. However, treatment of an infection does not necessarily reverse established testicular damage.
Treating Varicocele
When a clinically significant varicocele is contributing to fertility problems, surgical treatment may be considered in appropriate patients.
Addressing Hormonal Problems
If infertility is caused by an endocrine or hormonal disorder, treatment may involve addressing the underlying hormonal problem.
Importantly, men trying to conceive should not start testosterone replacement on their own, because external testosterone can suppress sperm production.
Fertility Treatment
If sperm production remains impaired, assisted reproductive techniques may provide options depending on the individual case.
Testicular Atrophy and IVF
If testicular atrophy is associated with severely reduced sperm production, IVF with ICSI may be considered.
ICSI involves injecting a single sperm directly into an egg during the IVF process. In some men with severe sperm-production problems, sperm may need to be retrieved directly from the testicle or reproductive tract for use in assisted reproduction.
The appropriate approach depends on whether sperm are present in the ejaculate, whether sperm production is occurring within the testicles, the underlying diagnosis and the fertility status of the female partner.
Can Men With Testicular Atrophy Still Have Children?
Yes, in some cases.
The possibility of biological fatherhood depends on factors such as:
- Whether one or both testicles are affected
- The underlying cause
- Remaining sperm production
- Hormonal function
- Semen analysis results
- Genetic factors
- Whether sperm can be retrieved surgically
Even when sperm are not found in the ejaculate, sperm retrieval procedures may sometimes provide sperm for use with IVF-ICSI.
This is why a diagnosis of testicular atrophy should not immediately be considered a diagnosis of permanent infertility.
When Should You See a Male Fertility Specialist?
You should consider a medical evaluation if you notice:
- A testicle becoming smaller
- A significant difference in testicular size
- Testicular pain, swelling or a lump
- A history of testicular injury or infection
- Previous undescended testicle
- Varicocele
- Low sperm count or abnormal semen analysis
- Difficulty achieving pregnancy
- A history of anabolic steroid or testosterone use
Men with fertility concerns should undergo an appropriate evaluation rather than assuming that the problem is solely related to their partner. Male factors contribute to infertility in a substantial proportion of couples.
Testicular Atrophy and Male Fertility: The Key Takeaway
Testicular atrophy is a sign that requires evaluation, not a final diagnosis of infertility. The effect on fertility varies considerably depending on the cause and how much testicular function remains.
A detailed evaluation with semen analysis, hormonal testing, physical examination, ultrasound and, when appropriate, genetic testing can help identify the underlying problem and determine the most suitable fertility pathway.
At Zemya IVF & Fertility Clinics, male fertility evaluation can help identify conditions affecting sperm production and guide patients toward appropriate treatment options, including advanced assisted reproductive techniques when indicated.



