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Orchitis is swelling (inflammation) of one or both of the testicles.

Alternative Names:

Epididymo - orchitis; Testis infection


Orchitis may be caused by an infection. Many types of bacteria and viruses can cause this condition.

The most common virus that causes orchitis is mumps. It most often occurs in boys after puberty. Orchitis most often develops 4 to 6 days after the mumps begins. Mumps is now rare in the United States due to childhood vaccinations.

Orchitis may also occur along with infections of the prostate or epididymis.

Orchitis may be caused by a sexually transmitted infection (STI) such as gonorrhea or chlamydia. The rate of sexually transmitted orchitis or epididymitis is higher in men ages 19 to 35.

Risk factors for sexually transmitted orchitis include:

  • High-risk sexual behaviors
  • Multiple sexual partners
  • Personal history of gonorrhea or another STI
  • Sexual partner with a diagnosed STI

Risk factors for orchitis not due to an STI include:

  • Being older than age 45
  • Long-term use of a Foley catheter
  • Not being vaccinated against the mumps
  • Problems of the urinary tract that were present at birth (congenital)
  • Repeated urinary tract infections
  • Surgery of the urinary tract (genitourinary surgery)

Symptoms include:

Exams and Tests:

A physical exam may show:

  • Enlarged or tender prostate gland
  • Tender and enlarged lymph nodes in the groin (inguinal) area on the affected side
  • Tender and enlarged testicle on the affected side

Tests may include:


Treatment may include:

  • Antibiotics, if the infection is caused by bacteria. (In the case of gonorrhea or chlamydia, sexual partners must also be treated.)
  • Anti-inflammatory medicines
  • Pain medicines
  • Bed rest with the scrotum elevated and ice packs applied to the area
Outlook (Prognosis):

Getting the right diagnosis and treatment for orchitis caused by bacteria can most often allow the testicle to recover normally.

You will need further testing to rule out testicular cancer if the testicle does not completely return to normal after treatment.

Mumps orchitis cannot be treated, and the outcome can vary. Men who have had mumps orchitis can become sterile.

Possible Complications:

Some boys who get orchitis caused by mumps will have shrinking of the testicles (testicular atrophy).

Orchitis may also cause infertility.

Other potential complications include:

  • Chronic epididymitis
  • Death of testicle tissue (testicular infarction)
  • Fistula on the skin of the scrotum (cutaneous scrotal fistula)
  • Scrotal abscess

Acute pain in the scrotum or testicles can be caused by twisting of the testicular blood vessels (torsion). This is a medical emergency that requires immediate surgery.

A swollen testicle with little or no pain may be a sign of testicular cancer. If this is the case, you should have a testicular ultrasound.

When to Contact a Medical Professional:

See your health care provider for an exam if you have testicle problems.

Get emergency medical help if you have sudden pain in the testicle.


Things you can do to prevent the problem include:

  • Get vaccinated against mumps.
  • Practice safer sex behaviors to decrease your risk of STIs.

Mason WH. Mumps. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 240.

McGowan CC, Krieger J. Prostatitis, epididymitis, and orchitis. In: Bennett JE, ed . Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015:chap 112.

Nickel JC. Prostatitis and related conditions, orchitis, and epididymitis. In: Wein AJ, ed. Campbell-Walsh Urology. 10th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 11.

Review Date: 1/21/2015
Reviewed By: Scott Miller, MD, urologist in private practice in Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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