Small Testicles: Harmless Variation or a Sign of a Bigger Health Issue?

By Dr. David Samadi

Are small testicles a cause for concern? For most men, the answer is no. Testicles come in all shapes and sizes, and variations are often perfectly normal. It’s important to remember that what’s ‘average’ is just a range, and being on the smaller end of that range doesn’t necessarily indicate a problem. While it’s understandable that some men might be concerned about testicle size, particularly if they believe theirs are smaller than average, the truth is that testicular size alone rarely indicates a serious health issue.

Most urologists will state that men with small testicles generally present few problems. However, if there has been a noticeable decrease in size over time, it’s worth consulting a doctor to explore the cause.

Let’s take a closer look at what can influence testicle size, when it might signal a health problem, and what treatment options are available.

What’s Considered Normal?

Testicular size is typically measured from top to bottom in length. The average adult male testicle measures between 4.5 to 5.1 centimeters in length. Some asymmetry is normal—one testicle may hang lower or appear slightly larger than the other. These variations don’t typically affect function or fertility.

That said, certain conditions may lead to testicular shrinkage or underdevelopment, which could be worth discussing with a healthcare provider.

Possible Causes of Smaller Testicles

1. Low Testosterone (Hypogonadism)

One of the most common hormonal causes of smaller testicles is low testosterone, a condition where the body doesn’t produce enough of this critical male hormone.

Some men with low testosterone may notice a reduction in testicular size. However, you must evaluate the complete clinical picture—testicle size alone doesn’t determine a diagnosis.

Other symptoms of low testosterone may include:

• Reduced sex drive
• Erectile dysfunction
• Chronic fatigue
• Loss of muscle mass
• Depression or mood swings
• Difficulty concentrating

Low testosterone is a treatable condition. Blood tests can confirm the diagnosis and testosterone replacement therapy (TRT) can often restore hormone levels and improve symptoms.

2. Varicocele

A varicocele is an enlargement of the veins within the scrotum, similar to varicose veins in the legs. It’s a fairly common condition and is found in up to 40% of men experiencing infertility.

A varicocele may cause one testicle to appear smaller, often due to impaired blood flow and increased scrotal temperature. In many cases, this affects the left testicle more than the right.

Surgery to correct a varicocele is generally effective in treating the condition. After the procedure, testicle size and sperm production often improve, which can have a positive impact on fertility.

3. Congenital Disorders: Klinefelter Syndrome

Some men are born with genetic conditions that affect testicular development. One such condition is Klinefelter Syndrome, which affects approximately 1 in 500 to 1,000 male births.

Men with Klinefelter Syndrome have an extra X chromosome (XXY instead of the typical XY), which can interfere with normal male sexual development.

Common characteristics may include:

• Small testicles and penis
• Delayed or incomplete puberty
• Reduced facial and body hair
• Broader hips and narrower shoulders
• Breast tissue development (gynecomastia)
• Infertility
• Low muscle tone and coordination issues

About 50% of men with Klinefelter Syndrome have low testosterone levels, which can be treated with hormone therapy. Early diagnosis and working closely with an endocrinologist can help manage symptoms effectively and improve quality of life.

4. Testicular Atrophy

Atrophy refers to the shrinking or wasting away of tissue. Testicular atrophy can result from a variety of causes, including:

• Aging
• Untreated infections (e.g., mumps, STDs)
• Alcohol-related liver disease (cirrhosis)
• Hormonal imbalances
• Complications from inguinal hernia surgery

In particular, repeated surgeries for hernia repair may raise the risk of testicular atrophy due to potential damage to the blood vessels supplying the testes.

Treatment depends on the underlying cause. Infections or hormonal deficiencies may be managed with medication, while lifestyle factors like alcohol misuse may require behavioral changes.

When to See a Doctor

If you’ve always had small testicles but have no other symptoms, there’s likely nothing to worry about. But if you notice a sudden change in size, experience pain, swelling, or lumps, or are dealing with symptoms of low testosterone, it’s wise to schedule a visit with your healthcare provider or a urologist.

There’s no need for men to suffer in silence or make assumptions. If you’re concerned, remember that you have the power to take control of your health. Talk to your doctor. Many conditions affecting testicle size are treatable—and addressing them early can make all the difference.

Bottom Line

Small testicles are usually harmless and often just a natural variation. But in some cases, they could point to a hormonal imbalance, vascular issue, or congenital disorder. The key takeaway? Don’t ignore your concerns. Remember, all men are built differently, and what matters most is that everything works as it should. A simple consultation and a few tests can provide clarity, peace of mind, and, in some cases, the proper treatment to restore health and confidence.

All men are built differently. What matters most is that everything works as it should. And if it doesn’t, that’s what doctors are here for.

Dr. David Samadi is the Director of Men’s Health and Urologic Oncology at St. Francis Hospital in Long Island. He’s a renowned and highly successful board certified Urologic Oncologist Expert and Robotic Surgeon in New York City, regarded as one of the leading prostate surgeons in the U.S., with a vast expertise in prostate cancer treatment and Robotic-Assisted Laparoscopic Prostatectomy.  Dr. Samadi is a medical contributor to NewsMax TV and is also the author of two books, Prostate Cancer, Now What?  A Practical Guide to Diagnosis, Treatment, and Recovery, and The Ultimate MANual, Dr. Samadi’s Guide to Men’s Health and Wellness, available online both on Amazon and Barnes & Noble. Visit Dr. Samadi’s websites at robotic oncology and prostate cancer 911.