Differential Diagnosis for Testicular Swelling with Mild Pain

Single Most Likely Diagnosis

• Epididymitis: This is an inflammation of the epididymis, a tube at the back of the testicle that stores and carries sperm. It is often caused by a bacterial infection and can lead to testicular swelling and mild pain. The symptoms can be similar to those of other conditions, but epididymitis is a common cause of testicular pain and swelling, especially in sexually active men.

Other Likely Diagnoses

• Orchitis: Inflammation of one or both testicles, usually caused by bacterial or viral infections. It can cause pain, swelling, and tenderness in the testicles.
• Hydrocele: A condition where fluid accumulates in the scrotum, causing swelling of the testicle. It can be primary (idiopathic) or secondary due to other conditions like epididymitis or testicular torsion.
• Varicocele: An enlargement of the veins within the scrotum, similar to varicose veins. It can cause a feeling of heaviness or swelling in the testicle and is more common on the left side.

Do Not Miss Diagnoses

• Testicular Torsion: A medical emergency where the spermatic cord becomes twisted, cutting off the blood supply to the testicle. It causes severe pain and swelling but can initially present with mild pain. Early diagnosis and treatment are crucial to save the testicle.
• Testicular Cancer: Although less common, testicular cancer can present with a painless testicular mass or swelling. It's essential to examine and investigate any testicular swelling to rule out cancer.

Rare Diagnoses

• Spermatocele: A cystic structure that forms at the head of the epididymis and contains sperm. It can cause swelling but is usually painless.
• Cystic dysplasia of the testis: A rare congenital condition where cysts form within the testicle, leading to swelling.
• Henoch-Schönlein Purpura (HSP): A form of vasculitis that can affect the testicles, causing swelling and pain, although this is less common.