Urology • Infection & Inflammation

Epididymitis and Epididymo-orchitis

Medical terms: Acute Epididymitis • Epididymo-orchitis • Orchitis

Epididymitis is inflammation of the coiled tube behind the testicle that stores and carries sperm. When inflammation also involves the testicle, it is called epididymo-orchitis.

Infection is a common cause, but the responsible organism and safest treatment depend on urinary, sexual, procedural and general-health factors. Sudden severe testicular pain must be treated as possible torsion until urgently assessed.

Seek immediate medical care

Sudden Severe Testicular Pain?

Testicular torsion twists the spermatic cord and can interrupt blood flow to the testicle. It is a time-critical surgical emergency and cannot be safely excluded by assuming the pain is an infection.

Go to an emergency facility immediately for:

  • Sudden severe pain in one testicle or one side of the scrotum.
  • Pain with rapid swelling, nausea, vomiting or lower abdominal pain.
  • A testicle that appears higher or lies differently from usual.
  • A sudden episode that improves by itself—intermittent torsion can twist and untwist.
  • Severe pain without urinary symptoms, discharge or other evidence of infection.

Urgent hospital assessment is also needed for:

  • High fever, shaking chills, faintness, confusion or rapidly worsening illness.
  • Spreading redness, blistering, dark skin, a bad smell or severe tenderness around the genitals or perineum.
  • Severe swelling, uncontrolled pain or repeated vomiting.
  • Inability to pass urine or symptoms affecting someone with significant immune suppression.

Do not wait for a routine appointment or arrange a delayed scan independently when torsion is possible. Strong clinical concern may require surgical assessment even when ultrasound findings are not definitive.

What Do These Terms Mean?

The epididymis is a soft, tightly coiled tube attached behind each testicle. Sperm mature and pass through it before entering the vas deferens. Inflammation may remain limited to the epididymis or extend into nearby structures.

Epididymitis Inflammation centred on the epididymis, usually causing tenderness behind or beside one testicle with increasing scrotal pain and swelling.
Epididymo-orchitis Inflammation involving both the epididymis and testicle. The distinction may be made through examination and ultrasound, but initial infection assessment is similar.
Orchitis Inflammation centred on the testicle. Viral infections such as mumps are an important cause, particularly with bilateral symptoms or salivary-gland swelling.
Chronic epididymitis Discomfort lasting six weeks or more. Persistent symptoms require a broader assessment because infection, inflammation, tumour, tuberculosis and referred pain can overlap.

“Inflammation” Does Not Identify the Cause

Epididymitis can arise from sexually transmitted organisms, urinary bacteria or less common non-bacterial conditions. Choosing antibiotics from age alone is unreliable; examination, urine testing, exposure history and local resistance patterns matter.

What Symptoms Can Occur?

One-sided pain Tenderness often begins behind one testicle and worsens over several hours or days.
Warmth and swelling The scrotal skin may become warm, red or swollen, sometimes with a reactive hydrocele.
Urinary symptoms Burning, frequency, urgency, difficulty passing urine or cloudy urine may accompany urinary infection.
Urethral symptoms Penile discharge or urethral irritation can suggest an STI, but urethritis may cause no obvious symptoms.

Other possible symptoms include:

  • Fever, chills, tiredness or feeling generally unwell.
  • Lower abdominal, groin, pelvic or perineal discomfort.
  • Pain with ejaculation or blood in semen.
  • A thickened, tender area behind the testicle that remains palpable as swelling settles.
  • Symptoms on both sides, which should prompt consideration of viral or other causes.

Epididymitis often develops more gradually than torsion, but the patterns can overlap. Sudden onset, young age or absence of infection evidence should lower the threshold for emergency torsion assessment—not create reassurance.

What Can Cause Epididymitis?

Sexually transmitted infection Chlamydia and gonorrhoea are important causes; Mycoplasma genitalium may also be involved. Urethral infection can be present without discharge or burning.
Urinary or enteric bacteria Organisms such as E. coli may travel from the urinary tract. Risk rises with poor bladder emptying, enlarged prostate, catheter use, urinary abnormalities or infection.
Recent procedure Urinary instrumentation, catheterisation, prostate biopsy, surgery or occasionally vasectomy can change the likely organisms and influence investigation.
Viral orchitis Mumps can inflame one or both testicles, often after fever, headache and swelling near the jaw. Vaccination greatly reduces this risk but does not eliminate every viral cause.
Tuberculosis and uncommon infection Genitourinary tuberculosis may cause long-standing, recurrent or nodular epididymal disease, sometimes with a draining sinus. Exposure, immune status and regional risk matter.
Non-infectious inflammation Trauma, urine reflux, autoimmune disease and some prescription medicines are uncommon possibilities. Chronic pain may remain unexplained after infection is excluded.

Epididymitis is not automatically an STI, and an STI cannot be excluded solely because someone is older, has no discharge or reports low risk. A confidential, non-judgemental history guides the correct specimens and prevents both missed infection and unnecessary treatment.

Questions Your Doctor May Ask

How did the pain begin?

Exact onset, speed of progression, previous sudden episodes, nausea, trauma and the position of the testicle help assess torsion risk.

Are there urinary or urethral symptoms?

Burning, frequency, poor flow, retention, discharge and recent urine infections can point towards a urinary or sexually transmitted source.

Could there have been sexual exposure?

Recent partners, condom use, oral or anal exposure and previous STIs change which organisms need testing and treatment. These questions are routine clinical care, not a judgement.

Has anything affected the urinary tract?

Catheters, prostate procedures, surgery, stones, enlarged prostate and difficulty emptying the bladder influence the likelihood of enteric bacteria and possible recurrence.

Are there systemic or unusual features?

Mumps exposure or vaccination, tuberculosis contact, travel, immune suppression, medicines, diabetes, fever, weight loss or a draining sinus can redirect the investigation.

How is the Diagnosis Made?

Diagnosis combines history, examination and evidence of infection or inflammation. The clinician examines both testicles and epididymides and may also assess the abdomen, groins, penis, prostate, lymph nodes and skin according to the presentation.

1 Exclude a surgical emergency

Sudden onset, severe pain, nausea, abnormal testicular position or diagnostic uncertainty prompts immediate torsion assessment. A clinical emergency must not wait for routine tests.

2 Examine the scrotum and urinary tract

The location of tenderness, swelling, hydrocele, skin changes, urethral discharge and signs of urinary obstruction or systemic illness are documented.

3 Collect microbiology specimens

Midstream urine is sent for bacterial culture. First-void urine or a urethral sample is used for nucleic-acid testing for chlamydia and gonorrhoea when appropriate.

4 Use targeted blood tests

Blood count, inflammatory markers, kidney function, blood cultures or STI screening are selected according to fever, severity, antibiotic choice and exposure risk.

5 Assess the underlying cause

Poor flow, recurrent infection, high residual urine, childhood episodes or unusual chronic disease may require urinary-tract imaging, flow testing or specialist investigations.

When is Scrotal Ultrasound Used?

Doppler ultrasound assesses blood flow and can show an enlarged, hypervascular epididymis or testicle, reactive fluid, abscess or an alternative mass. It is particularly useful when the diagnosis is uncertain, examination is difficult or torsion or another pathology must be assessed.

Ultrasound has limitations. Partial or intermittent torsion can resemble inflammation, while a negative scan does not exclude epididymitis. Clinical judgement remains essential, and strong suspicion of torsion requires urgent surgical review even when imaging is not conclusive.

Follow-up ultrasound may be needed when a focal lump, abscess, infarction or tumour remains a concern, or when swelling does not resolve as expected after appropriate treatment.

How is Acute Epididymitis Treated?

When bacterial infection is likely, treatment is often started after appropriate specimens are collected rather than waiting several days for every result. The prescription must match the most likely organisms, local resistance, allergies, kidney function, drug interactions and illness severity.

Likely chlamydia or gonorrhoea Combination treatment is selected to cover gonorrhoea and chlamydia while test results are pending. A fluoroquinolone alone is not appropriate when gonorrhoea is possible.
Likely urinary or enteric bacteria An antibiotic reaching epididymal tissue is chosen using urine culture, resistance patterns, recent procedures and patient-specific safety factors.
Mixed risk Coverage may be needed for both sexually transmitted and enteric organisms, including after relevant anal exposure. Test results then allow treatment to be narrowed or changed.
Severe or complicated infection Hospital care, intravenous antibiotics and fluids may be required. An abscess or dead tissue can require drainage, exploration or debridement in addition to antibiotics.
Viral or non-infectious disease Antibiotics do not treat viral orchitis or every chronic inflammatory condition. Treatment instead addresses the identified cause and provides appropriate pain and scrotal support.

Take antibiotics exactly as prescribed and complete the course unless the treating clinician changes it. Do not use leftover antibiotics, share medication or select a drug from an online regimen: resistance, gonorrhoea coverage, kidney function and drug safety can make the wrong choice ineffective or harmful.

What Supportive Care Helps Recovery?

  • Rest during the most painful inflammatory phase and gradually return to normal activity.
  • Support or elevate the scrotum with supportive underwear or a folded towel when lying down.
  • Apply a wrapped cold pack for short periods; never place ice directly on skin.
  • Use an appropriate pain-relief medicine only after checking that it is safe with existing conditions and other medicines.
  • Drink normally unless a clinician has advised fluid restriction for another medical reason.
  • Avoid heavy lifting, cycling and activities that clearly worsen pain until inflammation settles.

Fever and pain should begin improving within a few days of effective treatment, but thickening, tenderness and swelling can take several weeks to settle completely. Slow resolution is different from no improvement or deterioration, which requires reassessment.

What if an STI is Suspected or Confirmed?

  • Testing commonly includes chlamydia and gonorrhoea; HIV, syphilis and other tests are selected by risk and local guidance.
  • Recent sexual partners may need confidential notification, testing and treatment even when they have no symptoms.
  • Avoid sexual contact until treatment requirements are completed, symptoms have resolved and partners have been treated as advised.
  • Use condoms consistently after treatment and arrange retesting when recommended.
  • Do not assume a positive result proves when infection occurred; some infections remain silent for a long time.

Partner management prevents reinfection and further transmission. The exact look-back period and abstinence advice depend on the organism and local public-health protocol, so follow the instructions from the treating clinic rather than relying on a generic timetable.

When is Further Investigation Needed?

Reassessment is important when:

  • Symptoms are not clearly improving within 72 hours of starting treatment.
  • Pain, fever or swelling worsens at any point.
  • A firm area or testicular enlargement persists after antibiotics are completed.
  • Episodes recur or urine cultures repeatedly grow urinary bacteria.
  • Symptoms last six weeks or more, become bilateral or are associated with weight loss or a sinus.
  • There is poor urine flow, incomplete emptying, catheter use or a known urinary abnormality.

The clinician may reconsider torsion, abscess, infarction, testicular tumour, tuberculosis, fungal infection, chronic pain or a structural urinary problem. Persistent swelling should not simply be treated with repeated antibiotic courses without confirming the diagnosis.

Can Complications Occur?

Abscess or severe infection Pus can collect within the epididymis or testicle, and infection can rarely spread to the bloodstream or genital soft tissues. Drainage or surgery may be needed.
Reduced blood supply Severe swelling can rarely compromise testicular circulation, causing infarction, shrinkage or loss of testicular tissue.
Fertility effects Semen quality may fall temporarily during acute inflammation. Permanent fertility impact is uncommon after a straightforward one-sided episode but is more concerning with bilateral or severe disease.
Chronic pain or recurrence Residual tenderness can persist after infection clears. Recurrent episodes require evaluation for urinary obstruction, structural disease, ongoing exposure or a non-infectious diagnosis.

Myth vs Fact

Myth All epididymitis is sexually transmitted.
Fact STIs are important causes, but urinary bacteria, procedures, viral illness and non-infectious inflammation are also possible. Testing identifies the pathway.
Myth A normal ultrasound proves the pain is harmless.
Fact Partial or intermittent torsion can be difficult to distinguish, and a negative scan does not exclude epididymitis. Examination and clinical timing remain essential.
Myth Once antibiotics start, swelling should disappear immediately.
Fact Pain and fever should begin improving within a few days, but swelling may take weeks. No improvement by 72 hours or a persistent lump needs reassessment.

Frequently Asked Questions

How can I tell epididymitis from testicular torsion?

Epididymitis often worsens gradually and may accompany urinary symptoms or discharge, while torsion often starts suddenly with severe pain, nausea or an abnormal testicular position. The overlap is too important for self-diagnosis: sudden or severe pain needs emergency assessment.

Do I always need an ultrasound?

Not always. It is particularly useful when torsion or another condition must be excluded, the examination is unclear, or a complication is suspected. Urine and STI tests remain important because ultrasound does not identify the responsible organism.

How quickly should antibiotics work?

Pain, fever and general illness should begin improving within about 72 hours. Residual swelling may take much longer. Return sooner if symptoms worsen, and arrange reassessment if there is no clear improvement after three days.

Can epididymitis affect fertility?

Semen quality can be temporarily affected. Lasting fertility problems are uncommon after a treated one-sided episode but are more possible with severe, recurrent or bilateral inflammation. Discuss semen assessment if fertility is a concern after recovery.

Can I have sex during treatment?

If an STI is possible, avoid sex until you and relevant partners have completed the advised treatment, symptoms have resolved and the treating clinic says it is safe. Sexual activity may also worsen discomfort during the acute inflammatory phase.

Why does the lump remain after the pain improves?

Inflamed tissue can stay thickened for several weeks. A persistent, enlarging or hard area still requires examination and sometimes repeat ultrasound to exclude abscess, tumour or another diagnosis.

When can I return to exercise?

Resume gradually after fever has settled and walking is comfortable. Delay cycling, running, heavy lifting and contact sport if they increase pain or swelling, and use scrotal support during recovery.

A Note From Our Doctors

The information on this page is intended to help you understand your condition. It should not be considered a diagnosis or a substitute for a consultation with a qualified medical professional.

Every patient is unique. The same symptom can have different causes in different individuals, and the most appropriate investigations and treatment depend on your medical history, examination findings, age, existing medical conditions and test results.

At SR Speciality Hospital, we believe in treating the whole patient—not just a symptom, scan or laboratory report. Every treatment plan is individualised after careful medical evaluation.

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Living with scrotal pain, swelling or a suspected infection?

Arrange a prompt assessment for examination, appropriate urine and infection tests, and treatment matched to the likely cause. Sudden severe pain requires emergency care.