What Is Epididymitis?

The epididymis -- a long, coiled tube at the back of each of a man’s two testicles -- can get inflamed. When that happens, it’s called epididymitis.

It’s usually caused by a sexually transmitted infection, but several other types of bacteria can cause epididymitis as well.

What Does the Epididymis Do?

The epididymis carries sperm from the testes, which produce it, to the vas deferens, a tube behind the bladder.

The epididymis lays in coils around the back of a man’s testicle and can be nearly 20 feet long.

It can take nearly 2 weeks for sperm to make it from one end of the epididymis to the other. In that time, the sperm cells mature to the point where they’re able to fertilize a woman’s egg cell.


The most common causes of epididymitis are a pair of sexually transmitted infections: gonorrhea and chlamydia.

About 600,000 cases of epididymitis are reported in the United States every year, mostly in men between 18 and 35. In men older than 35, epididymitis usually happens because of an infection of the bladder or urinary tract.

Some cases of epididymitis are caused by the E. coli bacteria, or in rare cases, by the same bacteria that causes tuberculosis.


When a bacterial infection strikes, the epididymis gradually becomes swollen and painful. This usually happens on one testicle, rather than both. It can last up to 6 weeks if untreated.

You might have one or more of these other possible symptoms:

  • Redness, swelling, or tenderness in the scrotum, the sac that contains the testes
  • A more frequent or urgent need to pee
  • A lump on your testicle
  • Painful urination or ejaculation
  • Fever
  • Bloody urine
  • Discomfort in your lower abdomen
  • Enlarged lymph nodes in your groin
  • A lump on your testicle

See your doctor if you have any of these symptoms.


Related Conditions

Epididymitis shares many of the symptoms of a more serious problem called testicular torsion (that’s when a testicle gets turned around the cord that connects it to the body).

Testicular torsion symptoms usually develop much faster, however. Torsion is an emergency that may cause you to lose a testicle if you don’t get treatment quickly.

When the swelling and tenderness extends past the epididymis and into the testicle itself, that’s known as epididymo-orchitis.

Diagnosis and Tests

When you go to the doctor, he will examine your scrotum for signs of infection and ask you questions about your symptoms. He might also do a rectal exam to check your prostate and check for any tenderness.

If your doctor suspects epididymitis based on the exam, you might get one or more tests. They include:

  • Urine sample: You may pee into a cup so a lab can check for signs of an infection.
  • Blood sample: This can also find abnormalities.
  • Swab sample: For this test, your doctor inserts a narrow swab into the tip of your penis to get a sample of discharge. This is used to test for chlamydia or gonorrhea.
  • Ultrasound: You might also be asked to sit for an ultrasound test, which uses sound waves to produce an image of your scrotum and testicles.


The most common treatment for epididymitis is antibiotics. If your doctor believes you have epididymitis, he might give you a prescription for antibiotics before any lab test results are even back.

You’ll likely take those medications for a week or two, and you’ll usually start feeling better in a matter of days. Always take your full course of antibiotics as prescribed, even when you feel better.

Even after your antibiotics take effect, some swelling may last for weeks or months, and you may still be sore during that time. You can reduce the pain and swelling by taking over-the-counter pain relievers, applying a cold compress, or elevating your scrotum (you might wear supportive underwear, like a jockstrap).


Possible Complications

If left untreated, epididymitis can become a “chronic” condition, one that lingers and causes recurring problems.

Epididymitis might also cause in infection in the scrotum.

In rare cases, it can damage a man’s ability to make a woman pregnant.

Tell Your Partners

If your condition is the result of a sexually transmitted disease, you should tell anyone with whom you have had sex in the past 60 days about your diagnosis. If it’s been more than 60 days since you had sex, contact your most recent sex partner.

They should see a doctor and get tested for sexually transmitted diseases as well.

WebMD Medical Reference Reviewed by Carol DerSarkissian on December 28, 2018



CDC: “Epididymitis.”

American Urology Association: “Pathology for urologists -- Epididymitis.”

Cornwall, G., and von Horsten, H. The Genetics of Male Infertility: Sperm Maturation in the Epididymis. Humana Press, 2007.

American Family Physician: “Epididymitis and Orchitis: An Overview.”

Urology Care Foundation: “Epididymitis and Orchitis.”

The Mayo Clinic: “Epididymitis,” “Epididymitis: Diagnosis and Tests.”

National Health Services (UK): “Epididymitis.”

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