I'm a young to middle-aged adult male with no known underlying medical conditions, and I've noticed that my testicles aren't contracting during erections, making them appear smaller than usual, is this normal?

Testicular Contraction During Erection: Clinical Significance and Evaluation

The absence of testicular contraction (cremasteric reflex) during erections is a normal anatomical variation and does not indicate any pathology or require treatment. 1

Understanding Normal Testicular Behavior

The concern you're describing relates to the cremasteric reflex, which causes testicular elevation and is controlled by the cremaster muscle. This reflex varies significantly between individuals and is not a required component of normal erectile function. 1

Key points about testicular position and size:

• Testicular position during arousal is highly variable and depends on cremasteric muscle tone, temperature, and individual anatomy—there is no "normal" pattern that all men should exhibit 1

• Perceived testicular size changes are typically due to scrotal muscle contraction (dartos and cremaster muscles) rather than actual testicular volume changes 1

• Actual testicular atrophy is defined as volume <12 mL measured by Prader orchidometer or ultrasound, not by visual appearance during erections 2

When to Seek Medical Evaluation

While your specific concern about contraction during erections is not pathological, you should undergo evaluation if you have any of the following:

Testicular size concerns requiring assessment: 2

• Testicular volume that measures <12 mL on physical examination
• Noticeable asymmetry between testicles (>20% volume difference)
• Progressive testicular shrinkage over time
• History of undescended testicles (cryptorchidism)

Associated symptoms warranting evaluation: 1

• Erectile dysfunction (difficulty achieving or maintaining erections)
• Decreased libido or sexual desire
• Infertility concerns or difficulty conceiving
• Testicular pain or discomfort
• Palpable masses or lumps in the testicles

Recommended Evaluation if Concerned About Testicular Size

If you remain concerned about testicular size (not just appearance during erections), the following evaluation is indicated: 2, 3

1. Physical examination with precise measurement:

   • Testicular volume assessment using Prader orchidometer
   • Assessment for varicocele (dilated veins in scrotum)
   • Evaluation for testicular masses 1, 2

2. Hormonal evaluation (morning blood draw): 2, 3

   • Total testosterone
   • Follicle-stimulating hormone (FSH)—most important marker of testicular function
   • Luteinizing hormone (LH)
   • Sex hormone-binding globulin (SHBG)
   • Prolactin

3. Semen analysis if fertility is a concern: 1, 2

   • Two separate analyses 2-3 months apart
   • Evaluates sperm concentration, motility, and morphology

4. Scrotal ultrasound if indicated: 1, 2

   • When physical examination is difficult
   • To detect testicular tumors (higher risk in men with small testicles or history of cryptorchidism)
   • To identify varicocele or other structural abnormalities

Common Pitfalls to Avoid

Do not confuse normal anatomical variation with pathology. The cremasteric reflex and testicular position vary widely among healthy men and are influenced by temperature, arousal level, and individual anatomy. 1

Visual assessment of testicular size is unreliable. Scrotal skin thickness, body habitus, and cremasteric muscle tone all affect appearance. Only objective measurement (orchidometer or ultrasound) can accurately determine testicular volume. 1, 2

Normal testosterone levels do not exclude testicular dysfunction. FSH is the most sensitive marker—levels >7.6 IU/L indicate impaired spermatogenesis even when testosterone is normal. 2

Psychological Considerations

If this concern is causing significant anxiety or affecting your sexual function, consider evaluation by a mental health professional specializing in sexual health. 1 Performance anxiety and body image concerns can themselves contribute to sexual dysfunction, creating a self-perpetuating cycle. 1, 3