What could be causing testicular atrophy in a 30-year-old man with noticeably smaller, pendulous testicles?

Testicular Atrophy at Age 30: Evaluation and Management

You need a comprehensive evaluation immediately, starting with scrotal ultrasound to measure testicular volume and hormonal testing (FSH, LH, testosterone) to determine the cause of your testicular atrophy and assess your fertility status and cancer risk.

Understanding Your Symptoms

At 30 years old, noticeably smaller testicles compared to your penis size and increased pendulousness suggest testicular atrophy—a pathological reduction in testicular volume that warrants urgent investigation. 1

• Testicular volumes below 12 mL are definitively considered atrophic and associated with impaired sperm production, increased cancer risk, and potential infertility. 1
• The "dangling" you describe likely reflects loss of testicular mass rather than normal anatomical variation. 1

Immediate Diagnostic Steps

1. Scrotal Ultrasound with Volume Measurement

• Request high-frequency probe ultrasound (>10 MHz) to accurately measure testicular dimensions in three perpendicular planes (length, width, height). 1
• Volume should be calculated using the Lambert formula: Length × Width × Height × 0.71—not the traditional ellipsoid formula (0.52 coefficient), which systematically underestimates volume by 20-30%. 1
• Ultrasound will also exclude testicular masses, varicocele, and structural abnormalities. 1

2. Hormonal Evaluation

Obtain morning blood tests (8:00-10:00 AM) on two separate occasions to measure: 1

• FSH (follicle-stimulating hormone): Elevated FSH >7.6 IU/L indicates impaired spermatogenesis and testicular dysfunction. 2
• LH (luteinizing hormone) and total testosterone: This pattern distinguishes primary testicular failure (elevated LH/FSH with low testosterone) from secondary causes. 1
• Prolactin: To exclude hyperprolactinemia as a reversible cause. 1

3. Semen Analysis

• Perform at least two semen analyses 1-3 months apart with 2-3 days abstinence before collection. 3
• Testicular atrophy directly impairs sperm production, typically causing oligospermia (low sperm count) or azoospermia (absent sperm). 3
• If sperm concentration is <5 million/mL, genetic testing (karyotype and Y-chromosome microdeletion) is mandatory. 1

Critical Risk Factors to Assess

Cancer Risk

• Men under 30-40 years with testicular volume <12 mL have a ≥34% risk of intratubular germ cell neoplasia (TIN) if testicular cancer develops. 1
• If TIN is untreated, approximately 70% progress to invasive testicular cancer within 7 years. 1
• History of undescended testicles (cryptorchidism) dramatically increases both atrophy and cancer risk. 1, 3

Fertility Risk

• Testicular volume <12 mL strongly correlates with reduced total sperm count and impaired spermatogenesis. 1
• Even if you currently have sperm, reduced testicular reserve means higher risk of progressive decline. 2

Common Causes of Testicular Atrophy at Age 30

Primary Testicular Dysfunction (Most Common)

• Klinefelter syndrome (47,XXY): The most common genetic cause, presenting with small testes and elevated FSH. 1
• History of cryptorchidism: Even after surgical correction, causes permanent testicular damage. 1, 3
• Varicocele: Present in 35-40% of infertile men, causes progressive testicular atrophy through impaired blood flow. 3, 4
• Prior testicular torsion or trauma: Causes ischemic damage and atrophy. 3, 5
• Autoimmune orchitis: Can affect both testes with relatively painless atrophy. 1

Secondary Causes (Hormonal Suppression)

• Anabolic steroid or testosterone use: Completely suppresses sperm production and causes persistent atrophy for months to years after cessation. 1
• Chronic opioid use: Suppresses GnRH secretion, leading to low gonadotropins and bilateral atrophy. 1
• Hyperprolactinemia: From pituitary adenoma or medications. 1

Systemic Conditions

• Type 2 diabetes/metabolic syndrome: Linked to functional hypogonadism and reduced testicular volume. 1
• Chronic liver disease (cirrhosis): Contributes to secondary hypogonadism. 1
• HIV infection: Can cause both primary and secondary gonadal dysfunction. 1

Critical Actions to Protect Your Fertility

If You Want Children Now or in the Future:

1. Bank sperm immediately—collect 2-3 separate ejaculates before any intervention or while parameters remain normal. 2

   • Once azoospermia develops, even microsurgical sperm extraction only achieves 40-50% success rates. 2
   • Sperm banking provides insurance against progressive decline. 2

2. NEVER use exogenous testosterone or anabolic steroids if fertility is desired—these cause complete azoospermia that can take months to years to recover. 1, 2

3. Avoid gonadotoxic exposures: Heat (hot tubs, laptops on lap), smoking, excessive alcohol, and occupational toxins. 2

When to See a Urologist Urgently

Immediate urology referral is indicated if: 1

• Testicular volume confirmed <12 mL on ultrasound
• Age <30 years with history of cryptorchidism
• Palpable testicular mass develops
• FSH >7.6 IU/L with testicular atrophy
• Semen analysis shows severe oligospermia (<5 million/mL) or azoospermia

Treatment Options Based on Cause

If Varicocele is Present:

• Varicocele repair can halt progression of testicular atrophy and potentially reverse some damage, improving testosterone, reducing FSH, and stabilizing testicular volume. 2
• Repair is strongly indicated with documented atrophy, elevated FSH, and impaired semen parameters. 2

If Hormonal Dysfunction is Found:

• For secondary hypogonadism (low LH/FSH): hCG injections can stimulate testosterone and improve spermatogenesis, with 75% achieving sperm in ejaculate. 2
• For primary testicular failure: Assisted reproductive technology (IVF/ICSI) offers the best pregnancy rates. 2

If Non-Obstructive Azoospermia Develops:

• Microsurgical testicular sperm extraction (micro-TESE) achieves 40-50% sperm retrieval rates even with elevated FSH and small testes. 2

Critical Pitfalls to Avoid

• Do not delay evaluation—progressive testicular atrophy is often irreversible once advanced. 1
• Do not accept "normal" testosterone as reassurance—you can have normal testosterone with severely impaired sperm production. 1
• Do not start testosterone therapy without fertility evaluation—it will cause azoospermia. 1, 2
• Do not rely on single hormone or semen tests—repeat measurements are essential due to natural variability. 1, 2

Monitoring Protocol

• Repeat semen analysis every 6-12 months to detect early decline in sperm parameters. 2
• Teach yourself testicular self-examination given increased cancer risk with smaller volumes. 1
• Recheck hormones (FSH, LH, testosterone) after 3-6 months if initial values are borderline or after addressing reversible causes. 1