I have a swollen epididymis. Do I have an STI?

Published February 15 2024 inSexual Health
stopwatch2 minutes read

It can be incredibly upsetting to find something in your groin that wasn’t there before. However, in these situations, it’s best not to panic and to approach the situation with a clear head.

It’s not uncommon for men of a particular age to encounter a swollen epididymis. But what does having a swollen testicle epididymis mean? In this blog, we’ll cover what a swollen testicle might indicate and how you should respond if you find one yourself.

What is a possible cause of a swollen epididymitis?

The epididymis is a small, tube-like structure located at the back of the testicles. The epididymis carries sperm from the testes to the vas deferens. When this area becomes swollen and inflamed, it is known as epididymitis.

Symptoms of epididymitis include:

  • A swollen, discoloured scrotum
  • Severe pain and tenderness of the testicles
  • Pain during urination
  • Pain during sexual intercourse
  • Frequent urination
  • Pain in the lower abdomen or pelvic area
  • Bloody semen

Epididymitis that lasts longer than six weeks is known as chronic epididymitis.

There can be certain complications of epididymitis, including:

  • Abscesses in the scrotum
  • Hydroceles (a collection of fluid around the testicle)
  • Reduced fertility

Certain risk factors can make getting epididymitis more likely. These include:

  • Having sex with someone who has an STI
  • Unsafe sex (not using a condom)
  • Anal sex
  • Having a prior prostate or urinary tract infection
  • Medical procedures that affect the urinary tract, such as the insertion of a catheter
  • Not being circumcised
  • Abnormalities in your urinary tract anatomy
  • A large prostate gland
  • Health conditions that cause a weakened immune system, like HIV

What can cause a swollen epididymis?

A variety of factors can cause epididymitis. One common concern among people experiencing swelling in this area is whether it could be a sign of a sexually transmitted infection (STI). The STIs that cause epididymitis are bacterial or parasitic infections that infect the urinary tract, causing inflammation of the epididymis.

Here are some STIs that can cause epididymitis:

What else can cause a swollen epididymis?

Sexually transmitted infections aren’t the only causes of epididymitis. Other causes include:

  • Other infections: other bacterial infections can infect the urinary tract, such as a urinary tract infection (UTI) or a prostate infection
  • Urine in the epididymis: urine can sometimes flow backwards into the epididymis, causing irritation
  • Hydrocele: a thin sac of fluid on the testicle
  • Varicocele: an abnormal enlargement of the pampiniform venous plexus in the scrotum
  • Testicular torsion: when the spermatic cord, which provides blood flow to the testicle, twists and cuts off blood supply
  • Orchitis: an inflammation of one or both of the testicles, often accompanied by fever, nausea, vomiting, and blood in the semen, and epididymitis
  • Trauma: a groin injury can cause epididymitis
  • Tuberculosis: genitourinary tuberculosis, a form of tuberculosis that infects the genital tract, can cause epididymitis

Final thoughts

If you suspect an STI is causing your swollen epididymis, you should get tested as soon as possible.

Call the number at the top of this page to speak to one of Better2Know’s Sexual Health Advisors. They can discuss your symptoms and help you find the right sexual health clinic where you can get tested.


Mike has been delivering world class Sexually Transmitted Infections testing services to Better2Know patients around the world for over ten years. He has written extensively on the subject, including numerous blogs for Better2Know which are designed to demystify the complex intricacies of sexual health testing. Mike wants to help his readers understand the risks they take in their daily sexual lives and provide the information they need when choosing an STI or STD test in a clear, concise and understandable way. Mike is particularly interested in writing about viral STIs like HIV and Hepatitis, as these infections can have a devastating impact on people’s lives if they are not diagnosed quickly. Only through being well informed can you best care for your health, and Mike is passionate about sharing his knowledge and experience to help you and all his readers lead a happier, healthier life.