Why does acute orchitis occur?

The main causes of acute orchitis include: 1. Bacterial infection: In men with urethritis, prostatitis, or seminal vesiculitis, bacteria may invade the testis via the lymphatic system or through retrograde transmission along the vas deferens when immunity is compromised, leading to inflammation. 2. Mumps virus infection: The virus can reach the testis via hematogenous spread, particularly following an episode of epidemic mumps, making mumps orchitis likely. 3. Testicular trauma: If a testicular injury is not promptly treated, it may result in hematoma and subsequent secondary infection. 4. Iatrogenic infection: Medical procedures such as urethral instrumentation or indwelling catheterization may lead to iatrogenic infection of the testis.