Overview

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

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.

Causes

Orchitis can be caused by a bacterial or viral infection. Sometimes a cause of orchitis can't be determined (idiopathic orchitis).

Bacterial orchitis

Most often, bacterial orchitis is the result of epididymitis. Epididymitis usually is caused by an infection of the urethra or bladder that spreads to the epididymis.

Often, the cause of the infection is an STI. Other causes of infection may be related to having been born with abnormalities in your urinary tract or having had a catheter or medical instruments inserted into your penis.

Viral orchitis

Viral orchitis is usually caused by the mumps virus. About one-third of males who contract the mumps after puberty develop orchitis, usually four to seven days after onset of the mumps.

Risk factors

Risk factors for nonsexually transmitted orchitis include:

  • Not being immunized against mumps
  • Having recurring urinary tract infections
  • Having surgery that involves the genitals or urinary tract
  • Being born with an abnormality in the urinary tract

Sexual behaviors that can lead to STIs put you at risk of sexually transmitted orchitis. Those behaviors include having:

  • Multiple sexual partners
  • Sex with a partner who has an STI
  • Sex without a condom
  • A personal history of an STI

Complications

Complications of orchitis may include:

  • Testicular atrophy. Orchitis may eventually cause the affected testicle to shrink.
  • Scrotal abscess. The infected tissue fills with pus.
  • Repeated epididymitis. Orchitis can lead to recurrent episodes of epididymitis.
  • Infertility. Occasionally, orchitis may cause infertility or inadequate testosterone production (hypogonadism). But infertility and hypogonadism are less likely if orchitis affects only one testicle.
  • Infertility. Occasionally, orchitis may cause infertility. But infertility is less likely if orchitis affects only one testicle.

Prevention

To prevent orchitis:

  • Get immunized against mumps, the most common cause of viral orchitis
  • Practice safe sex, to help protect against STIs that can cause bacterial orchitis
Sept. 09, 2014
References
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  2. AskMayoExpert. What are the causes or types of scrotal masses? Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2013.
  3. Wein AJ, et al. Campbell-Walsh Urology. 10th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.clinicalkey.com. Accessed July 22, 2014.
  4. AskMayoExpert. What evaluation and treatment are indicated for orchitis as a cause of pediatric testicular or scrotal pain? Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
  5. Eyre RC, et al. Evaluation of the acute scrotum in adults. http://www.uptodate.com/home. Accessed July 18, 2014.
  6. Schaeffer AJ. Complications of urinary bladder catheters and preventive strategies. http://www.uptodate.com/home. Accessed July 18, 2014.
  7. Castle EP (expert opinion). Mayo Clinic, Phoenix, Ariz. Aug. 13, 2014.