Testicles are very sensitive. As a result, even a minor injury can cause pain or discomfort. Causes of testicle pain include:

• Infection or inflammation of the epididymis (epididymitis) or testicle (orchitis)
• Injury to the scrotum
• Impaired blood flow to the testicle due to twisting of the spermatic cord (testicular torsion) — most common in children
• A stone in the lower ureter, which can cause pain in the testicle on the same side as the stone
• A tumor
• Fluid in the testicles, such as due to a varicocele, spermatocele or hydrocele

Sudden, severe pain in the testicles requires emergency medical attention. Also, see your doctor if you have:

• Mild testicle pain lasting longer than a few days
• A lump or swelling in or around a testicle

The terms testicle pain and groin pain are often used interchangeably. But groin pain occurs in the fold of skin between the thigh and abdomen — not in the testicle. Causes of groin pain are different from causes of testicle pain.