Orchitis (or-KIE-tis) is an inflammation of one or both testicles. It is usually caused by a bacterial infection or by the mumps virus.

Bacterial orchitis can be caused by sexually transmitted infections (STIs), particularly gonorrhea or chlamydia. Bacterial orchitis often results from epididymitis, an inflammation of the coiled tube (epididymis) at the back of the testicle that stores and carries sperm. In that case, it's called epididymo-orchitis.

Orchitis causes pain and can affect fertility. Medication can treat the causes of bacterial orchitis and can ease some signs and symptoms of viral orchitis. But it may take several weeks for scrotal tenderness to disappear.

Symptoms Causes Risk factors Complications Prevention

Orchitis signs and symptoms usually develop suddenly and may include:

  • Swelling in one or both testicles
  • Pain ranging from mild to severe
  • Tenderness in one or both testicles, which may last for weeks
  • Fever
  • Nausea and vomiting

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

When to see a doctor

If you experience pain or swelling in your scrotum, especially if the pain occurs suddenly, see your doctor right away.

A number of conditions can cause testicle pain, and some of the conditions require immediate treatment. One such condition involves twisting of the spermatic cord (testicular torsion), which may cause pain similar to that caused by orchitis. Your doctor can perform tests to determine which condition is causing your pain.

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