Causes of Epididymitis

The epididymis is the tube that connects a man's testicle with his vas deferens. When the epididymis becomes swollen and inflamed, this condition is called epididymitis. Epididymitis occurs primarily in younger men between 19 and 35. According to the National Library of Medicine, it is a significant cause of hospital admissions in military populations. In most cases, epididymitis is caused by bacterial infection.

Chlamydia

Chlamydia, a sexually transmitted disease triggered by the bacterium Chlamydia trachomatis, causes 50 to 60 percent of epididymitis infections, according to eMedicine.com. The infection occurs when chlamydia bacteria travel from the urethra, the passageway from the bladder, into the epididymis. Men with epididymitis caused by chlamydia are usually prescribed antibiotics to treat the symptoms of infection.

Gonorrhea

The sexually transmitted disease gonorrhea, resulting from the bacterium Neisseria gonorrhoeae, also can cause epididymitis. Like a chlamydia-caused infection, this infection occurs when the bacteria travel from the urethra into the epididymis. Cases of epididymitis caused by gonorrhea are also treated with antibiotic therapy.

E. Coli

Bacteria that originate in the intestines, called Escherichia coli, can also cause epididymitis. Having anal intercourse without a condom can allow these bacteria to enter the urethra and travel to the epididymis, where they may cause infection. Unlike cases of epididymitis caused by chlamydia and gonorrhea, which mainly occur in men under 35, E. coli-caused epididymitis usually occurs in men over age 35 and those who have anal intercourse. These infections are also usually treated with antibiotics.

Other Bacterial Infections

Although chlamydia, gonorrhea, and E. coli infections are the most common causes of epididymitis, other types of bacteria, including tuberculosis and ureaplasma, can also lead to epididymitis, according to the National Library of Medicine.

Risk Factors for Epididymitis

Men who are uncircumcised, who have a history of urinary problems, who have recently undergone urinary tract surgery or who have unprotected sex with more than one partner are more likely to develop epididymis infections. Also, men taking the medication amiodarone for heart rhythm abnormalities may develop epididymitis.

In rare cases, men may have urine that flows backward from the urethra to the epididymis during heavy exercise or when having sex with a full bladder. The eMedicine website reports that this condition can cause the inflammation that is the hallmark of epididymitis.