[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Lower urinary tract and male genital system](https://durgical.com/en/general-pathology/areas/urinary-male/) › Testicular torsion

# Testicular torsion

- Lesion

Twisting of the spermatic cord blocks venous outflow first and then arterial supply; the testis can die within hours.

Updated Nov 12, 2026

## Key points

- Peak in adolescence; neonatal form is extravaginal.
- Bell-clapper deformity: abnormal mobility, often on both sides.
- Venous occlusion first, then arterial: hemorrhagic (red) infarction.
- Viability is high if untwisted within about six hours and falls sharply afterwards.
- The other testis is fixed surgically because the anatomical defect is often bilateral.

## What it is

Torsion of the spermatic cord occurs in two settings: in newborns, as extravaginal torsion in utero or shortly after birth, and in adolescents and young adults, usually intravaginal, through a bell-clapper deformity in which the tunica vaginalis surrounds the testis completely and lets it rotate freely. Twisting first obstructs thin-walled veins, causing congestion and hemorrhage, and then the arteries, causing hemorrhagic infarction. It is a urologic emergency.

## Structure

- Testis swollen, dark red to purple, with hemorrhage in the parenchyma and tunica.
- Microscopy: intense congestion, interstitial hemorrhage, then coagulative necrosis of tubules.
- Late: shrunken fibrotic testis.

## Clinical notes

- Sudden severe scrotal pain, often at night or after exercise, with nausea, a high-riding testis and absent cremasteric reflex.
- Doppler ultrasound shows absent flow, but imaging should not delay surgery when suspicion is high.

## Memory aid

Twist, swell, bleed, die: six hours to save the testis.

## Test yourself

Think of the answer, then tap the question to see it.

## What anatomical defect predisposes to torsion in adolescents?

The bell-clapper deformity, in which the tunica vaginalis surrounds the testis completely and leaves it free to rotate.

## Why is the infarction hemorrhagic?

Veins are compressed before arteries, so blood keeps entering but cannot leave.

## Why is the other testis fixed during surgery?

The predisposing anatomy is often bilateral.

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## Elsewhere in DurgiPedia

- [Infarction: red vs white, and what decides the damage](https://durgical.com/en/general-pathology/infarction-red-vs-white-and-what-decides-the-damage/)
- [Hemorrhage: petechiae, purpura, ecchymosis, hematoma, and what blood loss does](https://durgical.com/en/general-pathology/hemorrhage-petechiae-purpura-ecchymosis-hematoma-and-what-blood-loss-does/)

## Connections

## Related 4

- [Infarction: red vs white, and what decides the damage](https://durgical.com/en/general-pathology/infarction-red-vs-white-and-what-decides-the-damage/)
- [Hemorrhage: petechiae, purpura, ecchymosis, hematoma, and what blood loss does](https://durgical.com/en/general-pathology/hemorrhage-petechiae-purpura-ecchymosis-hematoma-and-what-blood-loss-does/)
- [Epididymitis, orchitis and prostatitis](https://durgical.com/en/general-pathology/epididymitis-orchitis-and-prostatitis/)
- [Cryptorchidism, testicular atrophy and reduced fertility](https://durgical.com/en/general-pathology/cryptorchidism-testicular-atrophy-and-reduced-fertility/)

## Related conditions 3

- [Testicular torsion](https://durgical.com/en/conditions/testicular-torsion/)
- [Cryptorchidism (undescended testis)](https://durgical.com/en/conditions/cryptorchidism/)
- [Epididymitis](https://durgical.com/en/conditions/epididymitis/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Testicular Torsion](https://www.ncbi.nlm.nih.gov/books/NBK448199/) (StatPearls (NCBI Bookshelf), 2024).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/general-pathology/testicular-torsion/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/testicular-torsion/