Epididymitis is inflammation of the epididymis, the tightly coiled tube at the back of each testicle that stores and transports sperm. It can cause scrotal pain, swelling, tenderness, and sometimes fever or urinary symptoms. In men’s health and fertility, epididymitis matters because it may affect comfort, sexual activity, sperm transport, and in some cases fertility—especially if it is severe, recurrent, or not treated promptly.
At a glance: epididymitis is often caused by a bacterial infection, including sexually transmitted infections (STIs) in some men, but it can also happen from non-sexually transmitted urinary bacteria, irritation, trauma, or less common inflammatory causes. Most cases improve with the right treatment, but sudden testicular pain should always be evaluated quickly because testicular torsion can look similar and is a medical emergency.
Key takeaways
- Epididymitis is inflammation of the epididymis, usually causing one-sided scrotal pain and swelling.
- In younger sexually active men, common causes include Chlamydia trachomatis and Neisseria gonorrhoeae; in older men, urinary tract bacteria are more common.
- Sudden severe testicular pain is not something to watch and wait on—testicular torsion must be ruled out quickly.
- Diagnosis may involve a physical exam, urine testing, STI testing, and often a scrotal ultrasound.
- Treatment depends on the cause and may include antibiotics, anti-inflammatory medicine, rest, and scrotal support.
- Most men recover well, but pain and swelling can take weeks to fully settle even after treatment starts.
- Severe, recurrent, or untreated epididymitis can sometimes affect sperm transport and fertility.
- Chronic scrotal pain lasting more than 6 weeks needs medical evaluation, even if infection is not found.
What is epididymitis?
The epididymis is a long, folded tube attached to the back of the testicle. Sperm mature and are stored there before moving into the vas deferens. Epididymitis means this structure has become inflamed. The inflammation can be due to infection, chemical irritation, or other causes.
Many people use “testicle infection” or “pain in the testicle” to describe it, but technically the main problem is usually in the epididymis rather than the testicle itself. Still, the two structures sit closely together, and inflammation can spread. When both are involved, the condition may be called epididymo-orchitis.
Where the pain is usually felt
Epididymitis often causes pain and tenderness toward the back or lower part of one testicle, though many men simply feel diffuse scrotal pain. The affected side may swell, feel warm, or appear red. The pain may build gradually over hours or days, but this is not always the case.
Why epididymitis matters for men’s health and fertility
For many men, epididymitis is both physically painful and mentally stressful. It can interfere with walking, exercise, sexual activity, sleep, and work. From a reproductive standpoint, the epididymis is where sperm mature and gain the ability to move effectively. Significant inflammation in this area can temporarily affect sperm quality, and in some cases may cause scarring or blockage that affects sperm transport.
This does not mean every episode leads to infertility. Most cases, especially when treated promptly, do not cause permanent reproductive problems. But the condition is important because it overlaps with infections, urinary tract issues, and emergencies that need timely care.
| Why it matters | Potential impact |
|---|---|
| Pain and inflammation | Can affect daily function, exercise, sex, and sleep |
| Infection risk | May reflect an STI or urinary tract source that also needs treatment |
| Fertility relevance | Severe or recurrent inflammation can sometimes impair sperm transport or semen quality |
| Diagnostic overlap | Can mimic testicular torsion, a time-sensitive emergency |
| Chronic symptoms | Some men develop prolonged scrotal discomfort even after infection resolves |
Symptoms of epididymitis
Epididymitis symptoms vary based on the cause and how quickly the inflammation developed. Many men have symptoms on only one side.
Common symptoms
- Scrotal pain, often one-sided
- Swelling or enlargement of the scrotum
- Tenderness behind or around the testicle
- Warmth or redness of the scrotal skin
- Pain that gets worse with walking, movement, or touch
- Painful urination or burning with urination
- Urinary urgency or frequency
- Discharge from the penis, especially if STI-related
- Fever or chills in some cases
- Pain with ejaculation or discomfort during sex
- Blood in semen or rarely blood in urine
How the pain often starts
Classically, epididymitis causes pain that comes on gradually, not instantly. But real-life presentations vary. Some men notice an ache first, then more obvious swelling later. Others present after several days of worsening symptoms. Because symptom patterns can overlap with other urgent causes of testicular pain, self-diagnosis is risky.
Causes and risk factors
The most common cause of epididymitis is infection, but not every case is infectious. The likely cause often depends on age, sexual history, urinary anatomy, medical history, and recent procedures.
Common infectious causes
- Sexually transmitted infections: especially chlamydia and gonorrhea, more common in younger sexually active men
- Urinary tract bacteria: such as E. coli, more common in older men or men with urinary tract abnormalities
- Post-instrumentation infection: after catheter use, cystoscopy, or other urologic procedures
- Prostate-related source: infection can spread from the prostate or urinary tract
Noninfectious or less common causes
- Chemical irritation from urine refluxing backward into the epididymis
- Trauma or repetitive strain
- Some inflammatory or autoimmune conditions
- Rare infections such as tuberculosis in select settings
- Medication-related inflammation in uncommon cases
Risk factors
- Unprotected sex or a new sexual partner
- History of STIs
- Recent urinary tract infection
- Enlarged prostate or urinary obstruction
- Catheter use or recent urologic procedure
- Structural abnormalities of the urinary tract
- Insertive anal intercourse, which may change the likely bacterial source
- Past episodes of epididymitis
Cause by age group: a simplified view
| Group | Common causes | Notes |
|---|---|---|
| Younger sexually active men | Chlamydia, gonorrhea | STI testing is often important |
| Men who practice insertive anal sex | STIs and enteric bacteria | Treatment may be adjusted based on likely organisms |
| Older men | Urinary tract bacteria, prostate-related infection | Urinary retention or prostate enlargement may contribute |
| After urologic procedures | Procedure-related bacterial infection | Recent instrumentation is an important clue |
Acute vs chronic epididymitis
Doctors often divide epididymitis into acute and chronic forms.
Acute epididymitis
Acute epididymitis usually lasts less than 6 weeks and is more often linked to infection. It tends to cause pain, swelling, and tenderness that are clearly noticeable and may worsen over a short period.
Chronic epididymitis
Chronic epididymitis refers to discomfort, pain, or inflammation in the epididymis lasting 6 weeks or longer. Infection may not be found. In some men, the issue becomes more about ongoing pain, nerve sensitivity, or persistent inflammation than an active bacterial infection.
| Feature | Acute epididymitis | Chronic epididymitis |
|---|---|---|
| Typical duration | Less than 6 weeks | 6 weeks or more |
| Common cause | Often infectious | May be inflammatory, post-infectious, or pain-related |
| Symptoms | More obvious swelling, tenderness, sometimes fever | Persistent ache, pressure, or recurrent discomfort |
| Treatment focus | Treat underlying cause, especially infection | Target pain, inflammation, and contributing factors |
How epididymitis is diagnosed
Diagnosis usually starts with a history and physical exam. A clinician will ask about pain onset, fever, urinary symptoms, sexual history, recent procedures, and whether symptoms are one-sided or sudden. The physical exam helps identify the epididymis, testicle, and surrounding tissues and assess whether the findings fit epididymitis or another condition.
Tests that may be used
- Urinalysis and urine culture: to look for signs of urinary infection.
- STI testing: especially nucleic acid amplification tests for chlamydia and gonorrhea.
- Scrotal ultrasound with Doppler: often used to assess blood flow, inflammation, swelling, and to help rule out testicular torsion.
- Physical exam: includes checking for scrotal swelling, tenderness, hernia, and discharge.
- Blood tests: sometimes used if symptoms are more severe, fever is present, or a broader infection is suspected.
Why ultrasound is often ordered
A scrotal ultrasound does not diagnose every case by itself, but it is very useful when the diagnosis is uncertain. The biggest reason is safety: reduced blood flow can suggest torsion, while increased blood flow and inflammation may support epididymitis.
Other things your clinician may consider
- Testicular torsion
- Orchitis
- Inguinal hernia
- Hydrocele or varicocele
- Kidney stone pain radiating to the groin
- Tumor or mass
- Chronic pelvic pain conditions
What’s normal vs what’s not?
Not every scrotal sensation is dangerous. Mild temporary discomfort after exercise, minor bumps, or brief positional sensitivity can happen. But persistent or worsening pain is not something to ignore.
| Situation | More likely normal or low concern | Needs prompt medical review |
|---|---|---|
| Brief mild tenderness | Settles quickly without swelling | Lasts or worsens over hours to days |
| Scrotal appearance | No redness, no visible swelling | Redness, swelling, warmth, enlarged side |
| Urinary symptoms | None | Burning, frequency, urgency, discharge |
| Pain pattern | Mild and improving | Moderate to severe or interfering with walking or sleep |
| General symptoms | No fever | Fever, chills, nausea, feeling unwell |
| Pain onset | Minor soreness after obvious strain | Sudden severe pain, especially with nausea or high-riding testicle |
Important: sudden severe testicular pain is not typical routine discomfort. It may be testicular torsion and should be treated as urgent.
Treatment options for epididymitis
Treatment depends on the most likely cause. If a bacterial infection is suspected, antibiotics are often started promptly—sometimes before every test result is back—because delaying treatment may prolong symptoms and increase complications.
Common treatment approaches
- Antibiotics: chosen based on whether the likely source is an STI, urinary bacteria, or both
- Anti-inflammatory medication: such as NSAIDs if appropriate for the patient
- Scrotal support: supportive underwear can reduce tugging and pain
- Rest and reduced activity: especially during the first few days
- Ice packs: short intervals may help swelling and discomfort
- Treatment of the underlying issue: such as urinary obstruction or prostate problems when relevant
If an STI is suspected
If chlamydia or gonorrhea is possible, sexual partners may also need testing and treatment. Men are usually advised to avoid sex until treatment is completed and symptoms have improved, following the guidance of their clinician.
If symptoms do not improve
Symptoms should begin to improve after treatment starts, but discomfort may not disappear immediately. If pain is worsening, fever persists, swelling increases, or there is little improvement after a few days, follow-up is important. A different diagnosis, resistant organism, abscess, or another complication may need to be considered.
What not to do
- Do not self-treat persistent testicular or scrotal pain as a pulled muscle without medical input.
- Do not use leftover antibiotics from a prior illness.
- Do not ignore symptoms because they “seem better” if swelling or tenderness remains significant.
- Do not resume strenuous exercise too soon if it clearly worsens symptoms.
Can epididymitis affect fertility?
Yes, it can—but the effect depends on severity, laterality, cause, and whether treatment is delayed. The epididymis is central to sperm maturation and transport. Inflammation here can temporarily disrupt normal sperm movement through the reproductive tract. Severe infection can also damage surrounding tissue.
Possible fertility effects
- Temporary decline in semen quality during or shortly after infection
- Reduced sperm motility if inflammation affects epididymal function
- Scarring or blockage in more severe cases
- Higher concern if both sides are affected or episodes recur
How common is permanent infertility after epididymitis?
Permanent infertility is not the typical outcome of a routine, promptly treated case. Still, unresolved infection, bilateral involvement, repeated infections, or associated complications can raise the risk. Men trying to conceive may want follow-up if they have had significant epididymitis, especially if pregnancy has not occurred after a reasonable period of trying.
When semen testing may be useful
A semen analysis may be considered if:
- You are actively trying to conceive
- You had severe or recurrent epididymitis
- Symptoms involved both sides
- You had surgery or concern for obstruction
- Conception has been delayed without a clear reason
Related fertility terms
- Oligozoospermia: low sperm count
- Asthenozoospermia: low sperm motility
- Azoospermia: no sperm seen in semen; in some cases obstruction is involved
- Obstructive infertility: sperm production may occur, but transport is blocked
Recovery and self-care
Even with proper treatment, recovery is not always instant. Pain often starts improving before swelling does. Residual tenderness can linger for days to weeks.
Typical recovery pattern
- Diagnosis and treatment begin
- Pain may start to improve over several days
- Swelling and tenderness gradually decrease
- Full resolution may take weeks in some men
Self-care during recovery
- Wear supportive underwear rather than loose boxers
- Rest and avoid heavy lifting if it worsens symptoms
- Use ice packs wrapped in cloth for short periods
- Take prescribed medicine exactly as directed
- Complete the full course of antibiotics if prescribed
- Attend follow-up if symptoms are not clearly improving
Can you exercise?
Light activity may be fine once pain is improving, but intense exercise, cycling, running, or weightlifting can worsen symptoms in the short term. Return gradually and let pain be your guide.
Can you have sex?
Sex may be uncomfortable during active inflammation. If an STI is involved or suspected, follow your clinician’s instructions about abstaining until treatment is complete and it is safe to resume sexual activity.
When to see a doctor urgently
Scrotal pain should not be ignored. Urgent evaluation is especially important if:
- The pain is sudden or severe
- The testicle is high-riding or sitting differently than usual
- You have nausea or vomiting with testicular pain
- You notice significant swelling, redness, or warmth
- You have fever or chills
- You have discharge from the penis or painful urination
- You recently had a urologic procedure or catheter
- Symptoms are not improving with treatment
If pain comes on suddenly, go for emergency care rather than waiting for a routine appointment.
Questions to ask your doctor
- Do my symptoms fit epididymitis, or could this be torsion or another cause?
- Do I need STI testing, urine testing, or a scrotal ultrasound?
- What is the likely cause in my case?
- How long should it take to improve after starting treatment?
- Should my sexual partner be tested or treated?
- When is it safe to resume sex, exercise, and heavy lifting?
- Could this affect my fertility or semen parameters?
- Would a semen analysis make sense if I’m trying to conceive?
- What should I do if pain remains after the antibiotics are finished?
Common myths and misconceptions
“Epididymitis always means an STI.”
No. STIs are one possible cause, especially in younger sexually active men, but urinary bacteria and noninfectious causes are also possible.
“If the pain fades, I don’t need treatment.”
Not necessarily. Symptoms can fluctuate. If infection is present, it still needs proper evaluation and treatment.
“All testicular pain is epididymitis.”
False. Torsion, hernia, trauma, orchitis, and other causes can produce similar symptoms.
“Epididymitis means I’ll become infertile.”
Most men do not become infertile from a routine treated episode. The fertility concern is higher when disease is severe, bilateral, recurrent, or prolonged.
FAQ
What does epididymitis feel like?
It often feels like one-sided scrotal or testicular pain with tenderness, swelling, warmth, and sometimes urinary burning or fever. The pain may start as an ache and worsen over time.
Can epididymitis go away on its own?
Some mild noninfectious irritation may improve with time, but true epididymitis should be medically assessed because infection is common and torsion must be ruled out in the right setting.
How long does epididymitis last?
Acute symptoms often begin improving within days of treatment, but residual swelling or tenderness can take weeks to fully resolve. Chronic epididymitis can last longer than 6 weeks.
Is epididymitis an STD?
Not always. It can be caused by sexually transmitted infections like chlamydia or gonorrhea, but it may also result from non-sexually transmitted urinary bacteria or other causes.
Can epididymitis affect sperm count or sperm quality?
It can, especially temporarily. Inflammation may affect sperm maturation and transport. Severe or recurrent cases may have a greater impact on semen parameters.
Do I need an ultrasound for epididymitis?
Not every case requires one, but scrotal ultrasound is commonly used when the diagnosis is uncertain or when testicular torsion needs to be excluded.
Can epididymitis cause infertility?
It can contribute to fertility problems in some cases, particularly if both sides are involved, if there is scarring or obstruction, or if treatment is delayed. Most treated cases do not cause permanent infertility.
Is epididymitis contagious?
The inflammation itself is not contagious. But if the underlying cause is an STI, that infection can be transmitted to sexual partners.
What is the difference between epididymitis and orchitis?
Epididymitis is inflammation of the epididymis. Orchitis is inflammation of the testicle. They can occur separately or together as epididymo-orchitis.
When should I worry about epididymitis symptoms?
Worry less about the label and more about the pattern: sudden severe pain, fever, rapidly increasing swelling, nausea, or a high-riding testicle all warrant urgent evaluation.
References
- Centers for Disease Control and Prevention. Sexually Transmitted Infections Treatment Guidelines.
- American Urological Association. Educational and clinical resources on acute scrotal conditions and male reproductive health.
- Merck Manual Professional Edition. Epididymitis.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Resources on urinary tract infections and urologic conditions.
- European Association of Urology. Guidelines on urological infections and acute scrotum.
- StatPearls Publishing. Clinical review content on epididymitis and acute scrotal pain.
