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

Epididymo - orchitis; Testis infection

Orchitis may be caused by an infection from many different types of bacteria and viruses.

The most common virus that causes orchitis is mumps. It most often occurs in boys after puberty. Orchitis usually develops 4 - 6 days after the mumps begins. Because of childhood vaccinations, mumps is now rare in the United States.

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

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

Risk factors for sexually transmitted orchitis include:

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

Risk factors for orchitis not due to an STD 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 occurred at birth (congenital)
• Regular urinary tract infections
• Surgery of the urinary tract (genitourinary surgery)

• Blood in the semen
• Discharge from penis
• Fever
• Groin pain
• Pain with intercourse or ejaculation
• Pain with urination (dysuria)
• Scrotal swelling
• Tender, swollen groin area on affected side
• Tender, swollen, heavy feeling in the testicle
• Testicle pain that is made worse by a bowel movement or straining

A physical examination 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:

• Complete blood count (CBC)
• Testicular ultrasound
• Tests to screen for chlamydia and gonorrhea (urethral smear)
• Urinalysis
• Urine culture (clean catch) -- may need several samples, including initial stream, midstream, and after prostate massage

Treatments 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 medications
• Pain medications
• Bed rest with the scrotum elevated and ice packs applied to the area

Getting the right diagnosis and treatment for orchitis caused by bacteria can usually preserve the normal testicle function.

If the testicle does not completely return to normal after treatment, further testing to rule out testicular cancer should be done.

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

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), which is a surgical emergency. If you have sudden pain in the scrotum or testicles, get immediate medical attention.

All testicle problems should be examined by a health care provider. 

Call your local emergency number (such as 911) or go to the nearest emergency room if you have sudden pain in the testicle.

Getting vaccinated against mumps will prevent mumps-associated orchitis. Safer sex behaviors, such as having only one partner at a time (monogamy) and condom use, will decrease the chance of developing orchitis as a result of a STI.

Krieger JN. Prostatitis, epididymitis, and orchitis. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone;2009:chap 109.

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

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