What Is Epididymitis?

It rarely starts with a bang. More often, a dull ache settles in at the back of one testicle, the scrotum gradually feels heavier and tender, and over a day or two the discomfort becomes hard to ignore. That pattern — a gradual build rather than a sudden crisis — is the classic signature of epididymitis, and this article walks through it step by step: what the condition is, how it is confirmed, and how it is treated. The short video at the top of this page, "Epididymitis" (1 minute 19 seconds), puts it plainly in its own description: epididymitis is infection, or less frequently inflammation, of the epididymis — the coiled tube on the back of the testicle — most cases develop because of a bacterial infection, and although males of any age can develop it, it occurs most frequently between the ages of 20 and 39.

Step one: understand what has become inflamed

The epididymis is a tightly coiled tube that sits behind each testicle, storing and carrying sperm as it matures. When bacteria reach it — commonly travelling back from the urinary tract or the prostate, and in younger men sometimes through a sexually transmitted infection — the tube becomes inflamed and swollen. That is why the tenderness is usually felt at the back of the testicle rather than in the testicle itself, and why the scrotum on that side can look a little swollen or feel warm. The same urinary route explains why epididymitis and urinary infections often travel together; our guide to what a urinary tract infection is covers that side of the picture.

Step two: get the cause sorted — and rule out the emergency

Here is the step that matters most, and it cannot be done from an article. Gradual pain points toward epididymitis, but sudden, severe testicle pain is a different story: it can be testicular torsion, where the cord twists and cuts off the blood supply, and that is a surgical emergency where hours count. Our article on testicular torsion explains that condition in detail. So the rule is simple — pain that comes on suddenly and strongly, or comes with vomiting or a high-riding testicle, needs emergency assessment the same day, not a wait-and-see approach. Slower-building pain still deserves a prompt appointment, because the treatment depends on which infection, if any, is behind it.

Step three: the examination and tests

At the appointment, expect the clinician to ask how the pain started, whether it came on gradually, and whether you have urinary symptoms, discharge, or a fever. Then comes a careful examination of the scrotum: in epididymitis the tender, swollen area is typically the epididymis at the back, and lifting the scrotum sometimes eases the discomfort a little. A urine test is a routine part of the work-up, and testing for sexually transmitted infections is often included, because finding the organism shapes the treatment. An ultrasound scan is added when the diagnosis is uncertain, when torsion cannot be confidently ruled out, or when things are not improving — it shows blood flow and swelling rather than relying on feel alone.

Step four: treatment, and giving it time to work

Because most cases are bacterial, antibiotics are the mainstay of treatment, chosen by the clinician according to the likely source of the infection — which is one reason the tests in step three matter. Alongside them, the everyday measures genuinely help: resting, supporting the scrotum, applying cold packs for short periods, and whatever pain relief your own clinician advises. One honest expectation to set: the pain usually starts easing within a few days of starting treatment, but the swelling and lumpiness can take weeks to fully settle, and that lingering tenderness on its own does not necessarily mean the treatment has failed. What does warrant a return visit is pain that is worsening, a fever that develops or persists, increasing swelling, or no improvement at all after a few days — occasionally an abscess or another cause is hiding underneath.

A close cousin worth knowing: orchitis

Sometimes the inflammation sits in the testicle itself rather than the tube behind it — that is orchitis, and the two conditions can overlap. The second video on this page, "Orchitis" (4 minutes 28 seconds), covers that condition; its description defines orchitis as an inflammation of one or both testicles, usually caused by a bacterial infection or by the mumps virus. The distinction matters to the clinician examining you, because the likely causes — and therefore the tests and treatment — are not identical, even though the symptoms can feel very similar from the patient's side of the examination couch.

Frequently Asked Questions

What does epididymitis feel like?

Typically a dull ache and tenderness at the back of one testicle that builds gradually over a day or two, often with scrotal swelling, a heavy feeling, and sometimes warmth or redness of the skin. Urinary symptoms or a mild fever can come with it. Sudden, severe pain is not typical — that pattern needs emergency assessment to rule out torsion.

How long does epididymitis take to clear?

The pain usually begins to ease within a few days once treatment starts, but swelling and a firm, lumpy feeling in the epididymis can linger for several weeks before the area feels completely normal again. Worsening pain, spreading swelling, or a new fever at any point is a reason to be seen again promptly.

Is epididymitis contagious?

The inflammation itself is not something you catch directly, but some of the infections that cause it — including certain sexually transmitted infections — can be passed to a partner. That is why testing is part of the work-up, why partners may need testing and treatment too, and why your clinician will advise on sex while you are being treated.

Can epididymitis come back?

It can. Recurrence sometimes means the original infection was not fully cleared, and sometimes it points to an underlying urinary-tract issue that keeps seeding new infections. Repeated episodes are worth a fuller urology work-up rather than simply repeating the same treatment each time.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician-scientist.

Educational only — this article is general information about epididymitis, not medical advice and not a diagnosis. Sudden, severe testicle pain is an emergency and needs same-day assessment; any scrotal pain or swelling should be examined by a clinician, who can assess you directly.