- Epididymitis is inflammation of the epididymis, one of the most common causes of acute scrotal pain, and most acute cases are bacterial and treatable with antibiotics.
- The cause varies by age: chlamydia and gonorrhea in sexually active men under 35, and enteric bacteria such as E. coli in older men or after urinary instrumentation.
- The critical task is ruling out testicular torsion, a surgical emergency in which sudden severe pain can save or lose the testicle within about six hours.
- CDC guidelines recommend ceftriaxone plus doxycycline for suspected STI cases, with a fluoroquinolone added or substituted when enteric organisms are likely; partners need treatment for documented STIs.
- Seek same-day care for new scrotal pain or swelling, and emergency care for sudden severe pain, high fever, or signs of sepsis.
The epididymis is the coiled tube where sperm mature, sitting along the back of each testicle, and when it becomes inflamed the result is one of the most common acute scrotal conditions in men. Epididymitis typically presents with gradual onset of scrotal pain and swelling, often accompanied by fever and urinary symptoms, and most acute cases are caused by bacterial infection that responds well to antibiotics. The critical task in evaluation is distinguishing epididymitis from testicular torsion, a true surgical emergency that can mimic similar symptoms.
Important: New or sudden scrotal pain and swelling need prompt, same-day medical evaluation. Sudden, severe testicular pain should be treated as possible testicular torsion — a surgical emergency — until a clinician proves otherwise. This article is educational and not a substitute for professional medical care; do not attempt to self-diagnose or self-treat scrotal pain.
What Epididymitis Is
Inflammation of the epididymis can be acute (less than 6 weeks) or chronic (more than 3 months). Most acute cases are bacterial, with infection ascending from the urethra and bladder through the vas deferens. According to the CDC’s 2021 STI Treatment Guidelines, which remain the current U.S. reference, the responsible organism varies by age and exposure. In sexually active men under 35, sexually transmitted bacteria like Chlamydia trachomatis and Neisseria gonorrhoeae predominate. In men over 35, those with urinary instrumentation, and men who practice insertive anal sex, gut (enteric) bacteria like E. coli become more common.
When inflammation extends to the testicle, the condition is called epididymo-orchitis. Mumps and other viral infections can cause primary orchitis, particularly in adolescents and adults who develop mumps after puberty. A 2024 European guideline on epididymo-orchitis broadly echoes the CDC’s age- and exposure-based approach to choosing antibiotics.
Symptoms
Acute epididymitis typically develops over 1 to 2 days, though some cases evolve faster. Common symptoms include unilateral scrotal pain (usually starting at the back of the testicle), swelling and tenderness of the epididymis, redness and warmth of the overlying skin, fever and chills, urinary frequency, dysuria, urethral discharge (in STI-related cases), and pain with ejaculation. Pain may radiate to the groin or lower abdomen.
Chronic epididymitis presents with persistent or recurrent dull scrotal pain lasting at least 3 months, often without acute swelling. The cause is frequently unclear, and management overlaps with chronic pelvic pain syndrome in men. Because presentations vary and overlap with other conditions, a clinician’s exam is needed to confirm the diagnosis.
The Critical Differential: Testicular Torsion
Testicular torsion is a surgical emergency in which the testicle twists on its spermatic cord, cutting off blood supply. Without detorsion within about 6 hours, the testicle is often lost. Torsion is most common in adolescents and young adults, while epididymitis is more common in sexually active adults. Torsion typically presents with sudden severe pain (over minutes), a high-riding testicle, an absent cremasteric reflex, and nausea or vomiting. Epididymitis is more gradual, with fever and urinary symptoms more prominent.
The distinction is not always clear at the bedside, and no single sign is reliable on its own. Doppler ultrasound assesses blood flow and is the standard imaging in any acute scrotum. When uncertainty remains, surgical exploration is preferred to a delayed diagnosis, because the cost of missing torsion is loss of the testicle. The medical conditions library includes related conditions that can present with scrotal pain.
How Epididymitis Is Diagnosed
Workup includes a detailed history (sexual exposure, urinary symptoms, recent instrumentation, fever, duration), physical exam, urinalysis with culture, and gram stain or nucleic acid amplification testing (NAAT) for chlamydia and gonorrhea. The classic Prehn’s sign (relief of pain with elevation of the scrotum) supports epididymitis over torsion but is unreliable enough that imaging is usually required.
Doppler ultrasound shows increased blood flow to the inflamed epididymis (and decreased or absent flow in torsion). It also evaluates for abscess, mass, or other complications. Blood work may show an elevated white cell count and inflammatory markers in significant infection. In sexually active men, testing for other STIs, including HIV and syphilis, is often recommended alongside the workup.
Treatment
Antibiotic Therapy
Treatment is empiric while culture results return, then adjusted as needed. For sexually active men under 35 with a suspected STI, the CDC recommends ceftriaxone 500 mg intramuscular in a single dose plus doxycycline 100 mg orally twice daily for 10 days (ceftriaxone is increased to 1 g for people weighing 150 kg or more). For men over 35, those with urinary instrumentation, or men who practice insertive anal sex, enteric organisms are more likely, and the CDC recommends adding or substituting a fluoroquinolone — for example, ceftriaxone 500 mg IM plus levofloxacin 500 mg orally once daily for 10 days, or levofloxacin alone for 10 days when an STI is not suspected. Regimens should be chosen by a clinician based on age, exposures, and local resistance patterns; sexual partners need treatment when STIs are documented. Do not attempt to self-medicate with leftover or online antibiotics.
Supportive Care
Bed rest, scrotal elevation with a supportive undergarment or rolled towel, ice packs, NSAIDs, and adequate hydration speed recovery. Pain typically improves within a few days of starting appropriate antibiotics, though residual swelling can persist for weeks.
Complications
Untreated or inadequately treated epididymitis can lead to abscess formation requiring drainage, chronic epididymitis, infertility (particularly with bilateral disease), and rarely sepsis. Recurrent or refractory cases warrant urology evaluation for underlying causes including BPH, anatomic abnormalities, or partial obstruction.
Long-Term Concerns and Fertility
Single episodes of acute epididymitis usually resolve without lasting effects. Severe, bilateral, or recurrent cases can damage the epididymal tubules, sometimes causing obstructive azoospermia or impaired sperm transport. Men concerned about fertility after significant epididymitis can consider semen analysis 3 to 6 months after recovery, once inflammation has fully settled.
When to See a Doctor
New scrotal pain, swelling, redness, fever, urinary symptoms, or urethral discharge warrants prompt evaluation. Most cases are evaluated in primary care, urgent care, or emergency departments depending on severity. Sudden severe pain is treated as torsion until proven otherwise.
When to seek emergency care: Call 911 or go to the nearest emergency room if you experience sudden severe testicular pain (testicular torsion is roughly a 6-hour surgical emergency to save the testicle), high fever with scrotal pain (possible abscess or sepsis), severe scrotal swelling, signs of sepsis (rapid heartbeat, confusion, low blood pressure), or an inability to urinate.
Frequently Asked Questions
Is epididymitis sexually transmitted?
It can be. In sexually active men under 35, chlamydia and gonorrhea are the most common causes. In older men and those with urinary catheters or instrumentation, gut bacteria are more common and not sexually transmitted. Partner notification and treatment matter when STIs are documented.
How long does epididymitis last?
Pain typically begins improving within 2 to 3 days of starting appropriate antibiotics. Residual swelling and tenderness can persist for several weeks. Full recovery usually occurs within 1 to 3 months, though this varies by severity and how promptly treatment starts.
Can I exercise with epididymitis?
Acute cases require rest, scrotal support, and avoidance of physical activity until symptoms improve substantially. Strenuous exercise typically resumes at 2 to 4 weeks depending on individual recovery. Follow your clinician’s specific guidance.
Will epididymitis affect my fertility?
Most single episodes do not. Severe, recurrent, or bilateral cases can damage epididymal tubules and impair sperm transport. Men with persistent fertility concerns should pursue semen analysis after full recovery.
Can epididymitis go away on its own?
Bacterial epididymitis generally needs antibiotics; waiting it out risks abscess, chronic pain, and, rarely, sepsis. Even if pain temporarily eases, an untreated infection can worsen or recur, so proper evaluation and a full antibiotic course are important.
What to Do Next
Acute scrotal pain and swelling deserve same-day evaluation. The most urgent task is distinguishing epididymitis from testicular torsion using exam, Doppler ultrasound, and clinical context. Once the diagnosis is confirmed, antibiotic therapy targeted to the most likely pathogens, supportive care, and follow-up to confirm resolution lead to full recovery in most men. Recurrent or chronic cases warrant a urology workup beyond a simple antibiotic course, since underlying anatomic or systemic factors are often present. When in doubt about severity, err toward being seen sooner rather than later.