Normal Testicular Position in the Scrotum
It is completely normal to have empty space above the testicles in the scrotum—the testicles do not need to fill the entire scrotal sac. The scrotum is designed with extra space to allow for temperature regulation, testicular mobility, and the cremasteric reflex that pulls the testes upward in response to cold or stimulation 1.
What Constitutes Normal Testicular Anatomy
Normal Testicular Position
- Fully descended testicles should be positioned within the scrotum but do not need to occupy the entire scrotal volume 1, 2.
- The scrotum naturally contains extra space above the testes, which serves important physiological functions including thermoregulation and allowing the cremasteric muscle to retract the testes when needed 1.
- Approximately 70% of undescended testes are palpable, meaning normal descended testes should be easily felt within the scrotum, but their position can vary 1.
Normal Testicular Size
- Normal adult testicular volume ranges from approximately 12-30 mL, with volumes below 12 mL considered small 3, 4.
- Testicular length typically measures 3.5-5.0 cm, width 2.5-3.5 cm, and depth 1.75-2.5 cm in normal fertile men 5, 6.
- Testicular size correlates directly with testicular function—smaller testes (below 14 mL) are associated with impaired sperm production 4, 7.
When Empty Space Above Testicles Is Concerning
Retractile Testes (Not Truly Abnormal)
- Some men have hyperactive cremasteric reflexes that cause the testes to retract upward frequently, creating more apparent empty space 1.
- Retractile testes can be manually manipulated back into the scrotum and remain there temporarily, distinguishing them from undescended testes 1.
- Men with retractile testes have a 2-45% risk of secondary testicular ascent (acquired cryptorchidism) and should monitor testicular position 1.
True Undescended Testes (Cryptorchidism)
- If a testis cannot be manipulated into the scrotum and maintained there, this represents true cryptorchidism requiring surgical evaluation 1, 2.
- Undescended testes are associated with increased risk of infertility and testicular cancer, even after surgical correction 1, 2.
- In adults with previously undiagnosed cryptorchidism, the affected testis is typically smaller and may have impaired function 1, 8.
Key Clinical Indicators to Assess
Signs That Your Anatomy Is Normal
- Both testicles can be easily palpated within the scrotum without needing to pull them down 1.
- Testicles feel firm, smooth, and approximately equal in size (slight asymmetry is normal) 9.
- No pain, swelling, or masses are present 10, 11.
Signs Requiring Medical Evaluation
- Inability to palpate one or both testicles in the scrotum, even with manual manipulation 1, 2.
- Marked size discrepancy between testicles (one significantly smaller than the other) 9, 3.
- Testicular volume estimated at less than 12 mL (roughly the size of a small walnut), which may indicate testicular atrophy or dysfunction 3, 4.
- History of undescended testicles in childhood, even if surgically corrected 1, 2.
Common Pitfalls to Avoid
- Do not confuse normal scrotal laxity and empty space with pathology—the scrotum is meant to have room for testicular movement 1.
- Cold temperatures or anxiety can cause temporary testicular retraction, making the empty space appear larger; this is a normal physiological response 1.
- Testicular self-examination should focus on detecting masses, asymmetry, or pain rather than worrying about scrotal filling 11.
When to Seek Medical Attention
Consult a healthcare provider if:
- You cannot locate one or both testicles in the scrotum consistently 1, 2.
- You notice progressive testicular shrinkage or new asymmetry 9, 8.
- You have concerns about fertility, as testicular size correlates with sperm production 4, 5, 7.
- You detect any lumps, pain, or swelling in the scrotum 10, 11.
Physical examination by a physician is the gold standard for assessing testicular position and size, with scrotal ultrasound reserved for cases where palpation is difficult or abnormalities are suspected 1, 11, 3.