Orchitis: Causes, Symptoms & Treatment of Testicular Inflammation

What Is Orchitis and How Does It Develop?

Orchitis is inflammation of one or both testicles, most commonly caused by bacterial infections spreading from the epididymis or by the mumps virus. It causes scrotal pain, swelling, and often fever. The condition is distinct from epididymitis (inflammation of the epididymis), though they frequently occur together as epididymo-orchitis.

The testicles are two oval-shaped glands located in the scrotum that produce sperm and the male hormone testosterone. When infection or inflammation affects the testicle itself, this is called orchitis. Understanding the anatomy helps explain why orchitis often occurs together with epididymitis: the epididymis is a coiled tube that sits behind each testicle and connects to the vas deferens. Infections can easily spread between these closely connected structures.

Orchitis is classified into two main types based on the underlying cause. Bacterial orchitis most commonly results from sexually transmitted infections such as chlamydia and gonorrhea in sexually active men, or from urinary tract infections in older men and children. Viral orchitis is typically caused by the mumps virus and occurs in approximately 25-35% of males who contract mumps after puberty. Before widespread MMR vaccination, mumps orchitis was much more common.

The inflammatory process in orchitis involves the body's immune response to the infectious agent. When bacteria or viruses invade the testicular tissue, white blood cells flood the area, causing swelling, increased blood flow (leading to warmth and redness), and the characteristic pain. This inflammatory response, while essential for fighting infection, can potentially damage the delicate sperm-producing cells if severe or prolonged, which is why prompt treatment is important.

Understanding Epididymo-Orchitis

In clinical practice, isolated orchitis (affecting only the testicle without the epididymis) is relatively uncommon except in mumps cases. More frequently, bacterial infections cause epididymo-orchitis, where both the epididymis and testicle are inflamed. This occurs because bacteria typically ascend through the urethra, travel through the vas deferens, and first infect the epididymis before spreading to the adjacent testicle.

The distinction between epididymitis and orchitis matters primarily for understanding the likely cause and expected course of the condition. Pure orchitis (without epididymal involvement) suggests a blood-borne viral infection like mumps, whereas epididymo-orchitis points toward an ascending bacterial infection. Your doctor will determine which structures are affected through physical examination and may use ultrasound imaging when the diagnosis is unclear.

Who Gets Orchitis?

Orchitis can affect males of any age, but certain populations face higher risk. Sexually active men aged 15-35 are most susceptible to STI-related bacterial epididymo-orchitis. Children and older men with urinary tract abnormalities or those who have had recent urological procedures are more prone to non-STI bacterial orchitis. Unvaccinated individuals of any age can develop mumps orchitis following mumps infection.

What Are the Symptoms of Orchitis?

The main symptoms of orchitis include scrotal pain (ranging from mild to severe), testicular swelling, redness and warmth of the scrotum, fever, nausea, and general malaise. Pain may develop gradually over several days with bacterial orchitis or appear suddenly with mumps orchitis. Painful urination suggests an underlying urinary tract infection.

The presentation of orchitis symptoms can vary depending on the underlying cause, but certain features are common to most cases. The hallmark symptom is scrotal pain, which typically affects one side initially, though both testicles can be involved simultaneously or sequentially. The pain often radiates to the groin and lower abdomen, making it difficult to walk or sit comfortably. Many men describe a heavy, dragging sensation in the affected side of the scrotum.

Swelling of the testicle is another cardinal sign, often making the affected testicle noticeably larger than the other. The scrotum on the affected side may appear red, feel warm to the touch, and become extremely tender even to light pressure. This inflammatory reaction can progress over several hours to days, reaching peak severity before treatment takes effect.

Systemic symptoms reflect the body's response to infection. Fever is common, ranging from low-grade (37.5-38.5°C / 99.5-101.3°F) in mild cases to high fever (above 39°C / 102.2°F) in severe infections. Many patients experience chills, fatigue, muscle aches, and loss of appetite. Nausea and occasionally vomiting can occur, particularly when pain is severe or fever is high.

Bacterial Orchitis Symptoms

When orchitis results from bacterial infection, symptoms typically develop gradually over one to several days. The pattern often begins with urinary symptoms such as burning during urination, increased urinary frequency, or urethral discharge - indicating that the infection started in the urinary tract before ascending to the reproductive organs. Pain may initially be localized to the epididymis (felt at the back of the testicle) before spreading to involve the entire testicle.

In STI-related cases, patients may notice penile discharge - clear, white, or yellowish depending on the causative organism. Chlamydia infections often produce minimal or no discharge, while gonorrhea typically causes more noticeable purulent discharge. Some men experience these urinary symptoms days to weeks before testicular pain develops, though others have no warning signs before scrotal symptoms begin.

Mumps Orchitis Symptoms

Mumps orchitis presents differently from bacterial orchitis. It typically develops 4-8 days after the onset of parotitis (the characteristic swollen cheeks of mumps), though it can occasionally occur without obvious parotid gland involvement. The testicular pain and swelling in mumps orchitis often appear more suddenly and can be quite severe, reaching maximum intensity within 24-48 hours.

Approximately 15-30% of mumps orchitis cases affect both testicles (bilateral involvement), though this may occur sequentially rather than simultaneously. The viral illness also causes the typical mumps symptoms: fever, headache, fatigue, loss of appetite, and painful swollen salivary glands. Recovery from mumps orchitis generally takes 1-2 weeks, though some residual swelling or tenderness may persist longer.

What Causes Orchitis?

Orchitis is caused by either bacterial infections (most commonly sexually transmitted infections like chlamydia and gonorrhea in younger men, or urinary tract infections in older men) or viral infections (primarily mumps). The route of infection differs: bacteria typically ascend from the urethra through the vas deferens, while viruses reach the testicle through the bloodstream.

Understanding the causes of orchitis helps guide both treatment and prevention strategies. The infectious agents responsible for orchitis reach the testicle through different pathways depending on whether the infection is bacterial or viral, and the specific cause has important implications for treatment and partner notification.

Sexually Transmitted Infections (STIs)

In sexually active men under 35, sexually transmitted infections account for the majority of bacterial orchitis cases. Chlamydia trachomatis is the most common causative organism, responsible for approximately 50-60% of STI-related cases. Neisseria gonorrhoeae (gonorrhea) accounts for another significant proportion. These bacteria initially infect the urethra during unprotected sexual contact, then ascend through the reproductive tract to reach the epididymis and testicle.

The ascending route of infection explains why STI-related orchitis almost always involves the epididymis first (epididymo-orchitis). The bacteria travel from the urethra, through the ejaculatory ducts, into the vas deferens, and finally reach the epididymis. From this closely connected structure, infection easily spreads to the adjacent testicular tissue. This progression typically occurs over days to weeks, though the speed varies based on the organism and individual factors.

Non-STI Bacterial Causes

In men over 35 and in children, non-sexually transmitted bacteria are more common causes of orchitis. These include Escherichia coli and other gram-negative bacteria that typically cause urinary tract infections. The same ascending pathway is involved, but the bacteria originate from the urinary tract rather than from sexual transmission.

Certain factors increase susceptibility to non-STI bacterial orchitis. Urinary tract abnormalities such as bladder outlet obstruction from an enlarged prostate, urethral strictures, or congenital malformations create conditions favorable for bacterial growth and ascending infection. Men who have had urological procedures or prolonged urinary catheterization face elevated risk. Recent inguinal hernia surgery can occasionally lead to orchitis as a post-operative complication.

Mumps and Other Viral Causes

The mumps virus (paramyxovirus) is the most common viral cause of orchitis, affecting approximately 25-35% of males who contract mumps after puberty. The virus spreads through respiratory droplets and causes systemic infection. Unlike bacterial orchitis, mumps virus reaches the testicle through the bloodstream (hematogenous spread) rather than ascending from the urinary tract.

The mumps virus has a particular affinity for glandular tissue, which explains why it affects the parotid salivary glands (causing the classic chipmunk cheeks appearance), pancreas, and testicles. Orchitis typically develops about a week after the parotid symptoms appear, though occasionally the testicular inflammation can be the first or only manifestation of mumps infection.

Other viruses can occasionally cause orchitis, though much less commonly than mumps. These include coxsackievirus, echovirus, and varicella (chickenpox/shingles virus). Rarely, HIV and adenoviruses have been associated with orchitis. Viral orchitis is generally a self-limiting condition that resolves with supportive care, unlike bacterial orchitis which requires antibiotic treatment.

Risk Factors Summary

How Can You Prevent Orchitis?

Orchitis can be prevented through vaccination against mumps (MMR vaccine), practicing safe sex with consistent condom use to prevent STIs, prompt treatment of urinary tract infections, and maintaining good hygiene. These preventive measures target the main causes of orchitis and can significantly reduce your risk.

Prevention strategies for orchitis focus on addressing the underlying causes before they can lead to testicular inflammation. Since bacterial and viral orchitis have different causes, the preventive approaches differ accordingly. Implementing these measures not only reduces orchitis risk but also protects against the broader health consequences of STIs and mumps.

Vaccination Against Mumps

The most effective prevention for viral orchitis is vaccination with the MMR (measles, mumps, rubella) vaccine. This vaccine has dramatically reduced the incidence of mumps and consequently mumps orchitis in countries with high vaccination coverage. The standard immunization schedule includes two doses: the first at 12-15 months of age and the second at 4-6 years.

Adults who have not been vaccinated or who received only one dose should consider getting the MMR vaccine, particularly if they plan to travel to areas where mumps is common or if they work in healthcare settings. The vaccine is highly effective, with two doses providing approximately 88% protection against mumps. Even when vaccinated individuals do contract mumps, the illness is typically milder, and complications like orchitis are less common.

Safe Sexual Practices

Consistent and correct condom use significantly reduces the risk of sexually transmitted infections that cause bacterial orchitis. Condoms provide effective barriers against chlamydia and gonorrhea when used properly during every sexual encounter. While not 100% effective, condoms substantially lower transmission risk compared to unprotected intercourse.

Other safe sex practices that reduce STI risk include: limiting the number of sexual partners, having mutually monogamous relationships with partners who have tested negative for STIs, and regular STI screening if you are sexually active with multiple partners or new partners. If an STI is diagnosed, abstaining from sexual activity until treatment is complete prevents transmission to partners and reduces the risk of complications including orchitis.

Prompt Treatment of Infections

Early treatment of urinary tract infections can prevent bacteria from ascending to the epididymis and testicle. If you experience symptoms of a UTI such as burning urination, frequent urge to urinate, or cloudy urine, seek medical attention promptly rather than hoping symptoms will resolve on their own. Similarly, any unusual urethral discharge should be evaluated and treated.

For men with known urinary tract abnormalities or those who have undergone urological procedures, following your doctor's recommendations for preventive measures is important. This may include prophylactic antibiotics before certain procedures and careful attention to catheter care if a urinary catheter is necessary.

When Should You See a Doctor for Testicular Pain?

Seek immediate emergency care if you experience sudden, severe testicular pain that doesn't improve within a few minutes - this could be testicular torsion. For gradually developing scrotal pain, swelling, or tenderness, especially with fever or urinary symptoms, see a doctor promptly (same day or next day). Early treatment prevents complications.

Knowing when to seek medical care for testicular symptoms is crucial because some conditions affecting the testicles are medical emergencies while others, though uncomfortable, can be evaluated on a less urgent basis. The key distinguishing feature is the onset and severity of pain.

Emergency Situations

Testicular torsion is the primary concern that requires emergency evaluation. In this condition, the testicle rotates on the spermatic cord, cutting off its blood supply. Without prompt surgical intervention (within 6 hours), the testicle can suffer permanent damage or die. Warning signs that suggest torsion include:

• Sudden, severe testicular pain that comes on abruptly
• Pain that does not improve with rest or position changes
• Nausea and vomiting accompanying the pain
• The affected testicle appearing higher than normal or lying horizontally
• Absent or reduced cremasteric reflex (the testicle doesn't rise when the inner thigh is stroked)

If you experience sudden severe testicular pain, go directly to an emergency department. Do not wait to see if symptoms improve. Time is critical for salvaging the testicle if torsion is present.

Urgent (Same-Day) Evaluation

While not as immediately life-threatening as torsion, orchitis and epididymitis benefit from prompt evaluation and treatment. Seek medical care the same day or next day if you experience:

• Scrotal pain that develops gradually over hours to days
• Testicular or scrotal swelling
• Fever along with scrotal symptoms
• Redness or warmth of the scrotum
• Pain that affects your ability to walk normally
• Urinary symptoms such as painful urination or discharge

Early treatment of bacterial orchitis with antibiotics leads to faster symptom relief and reduces the risk of complications such as abscess formation. Don't delay care hoping symptoms will resolve spontaneously.

Where to Seek Care

For sudden severe pain: go to the emergency department - this is the only appropriate option when testicular torsion is a possibility. For gradual-onset symptoms: you can see your primary care physician, an urgent care clinic, or a urologist. Many clinics can accommodate same-day appointments for concerning symptoms. If you cannot access same-day care and symptoms are worsening, an emergency department can evaluate you.

How Is Orchitis Diagnosed?

Doctors diagnose orchitis through physical examination of the scrotum, urine tests, STI screening (urethral swab or urine test for chlamydia and gonorrhea), blood tests for inflammation markers, and often scrotal ultrasound with Doppler to assess blood flow and rule out testicular torsion. The pattern of findings helps distinguish orchitis from other causes of scrotal pain.

Accurate diagnosis of orchitis involves differentiating it from other conditions that cause scrotal pain and swelling, particularly testicular torsion which requires emergency surgery. Your doctor will use a combination of clinical examination, laboratory tests, and imaging to reach the correct diagnosis and identify the underlying cause.

Physical Examination

The physical examination is the cornerstone of orchitis diagnosis. Your doctor will examine the scrotum by inspection and palpation (gentle touch), assessing for swelling, redness, warmth, and tenderness. Key findings that suggest orchitis include a swollen, tender testicle with normal lie (position), often with associated epididymal tenderness.

The doctor will check the cremasteric reflex by gently stroking the inner thigh and observing whether the testicle rises. This reflex is typically present in orchitis but absent in testicular torsion. The doctor will also assess whether elevating the testicle relieves pain (Prehn's sign) - pain relief with elevation suggests epididymo-orchitis rather than torsion, though this sign is not completely reliable.

Laboratory Tests

Urinalysis and urine culture help identify urinary tract infection as a contributing factor. The presence of white blood cells, bacteria, or nitrites in the urine suggests UTI. A urine culture identifies the specific bacteria and determines which antibiotics will be effective.

STI testing is essential for sexually active men with orchitis. This typically includes a nucleic acid amplification test (NAAT) for chlamydia and gonorrhea, which can be performed on a urine sample or urethral swab. Results are usually available within 1-3 days, though treatment may begin empirically before results return.

A blood test for C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) measures inflammation levels in the body. Elevated values support the diagnosis of an infectious/inflammatory process. A complete blood count may show elevated white blood cells, another indicator of infection.

Imaging Studies

Scrotal ultrasound with color Doppler is often performed when the diagnosis is uncertain or when testicular torsion needs to be ruled out. This painless imaging study shows the structure of the testicle and epididymis and, critically, assesses blood flow to the testicle. In orchitis, blood flow is typically increased (hyperemia) due to inflammation. In testicular torsion, blood flow is reduced or absent - this is a key distinguishing feature.

Ultrasound can also identify complications such as testicular abscess (collection of pus) or hydrocele (fluid accumulation around the testicle). If an abscess is present, this may require drainage in addition to antibiotic therapy.

How Is Orchitis Treated?

Treatment depends on the cause. Bacterial orchitis requires antibiotic therapy for 2-3 weeks, with most patients improving within 3 days. Viral (mumps) orchitis is treated with supportive care only, as antibiotics don't work against viruses. Both types benefit from rest, scrotal support, pain relievers, and ice application. Sexual partners need testing and treatment if an STI is the cause.

The treatment approach for orchitis depends primarily on whether the cause is bacterial or viral. Regardless of cause, supportive measures help reduce symptoms and promote healing. The goals of treatment are to eliminate the infection (in bacterial cases), relieve symptoms, prevent complications, and prevent transmission to partners (in STI cases).

Antibiotic Treatment for Bacterial Orchitis

Bacterial epididymo-orchitis requires antibiotic therapy selected to cover the likely causative organisms. For sexually active men under 35, treatment typically covers both chlamydia and gonorrhea:

• Ceftriaxone (single intramuscular injection) to cover gonorrhea
• Doxycycline 100mg twice daily for 10-14 days to cover chlamydia

For men over 35 or those where a non-STI cause is suspected (such as urinary tract infection), treatment focuses on covering gram-negative bacteria:

• Fluoroquinolone antibiotics such as levofloxacin for 10-14 days, OR
• Trimethoprim-sulfamethoxazole for a similar duration

Most patients experience significant improvement within 48-72 hours of starting antibiotics. However, it is crucial to complete the entire prescribed course even if you feel better. Stopping antibiotics early can lead to recurrence of infection and contribute to antibiotic resistance. Some residual swelling or mild discomfort may persist for several weeks after the infection has cleared.

Treatment for Viral Orchitis

Mumps orchitis and other viral causes do not respond to antibiotics since antibiotics only work against bacteria. Treatment is purely supportive, focusing on symptom relief while the body's immune system clears the virus. Viral orchitis typically resolves within 1-2 weeks, though complete resolution may take longer.

Supportive Care Measures

These measures help relieve symptoms in both bacterial and viral orchitis:

• Rest: Bed rest during the acute phase helps reduce pain and swelling. Avoid strenuous activity until symptoms have substantially improved.
• Scrotal support: Wearing an athletic supporter (jockstrap) or snug-fitting underwear supports the scrotum, reduces the pulling sensation, and can significantly improve comfort. A folded towel under the scrotum while lying down also helps.
• Ice application: Applying ice packs wrapped in a cloth to the scrotum for 15-20 minutes several times daily during the first 48-72 hours reduces swelling and provides pain relief. Never apply ice directly to skin.
• Pain medication: Over-the-counter analgesics such as paracetamol (acetaminophen) or NSAIDs (ibuprofen, naproxen) help control pain and reduce fever. Follow dosing instructions and be aware that NSAIDs should be used cautiously in people with kidney problems or certain other conditions.
• Hydration: Drink plenty of fluids, especially if you have fever.

Partner Notification and Testing

If orchitis is caused by a sexually transmitted infection, it is essential that sexual partners are notified, tested, and treated if necessary. This prevents re-infection of the patient and stops the chain of transmission. Partners from the past 60 days (or the most recent partner if longer than 60 days) should be contacted. Many health departments can assist with partner notification if needed.

Abstain from sexual activity until you have completed your antibiotic course and your partner(s) have been treated. Your doctor may recommend a test-of-cure (repeat STI testing) after treatment completion to confirm the infection has been eliminated.

Follow-Up Care

A follow-up appointment approximately 2-4 weeks after starting treatment allows your doctor to verify that the infection has resolved and that any swelling is decreasing. If symptoms persist, worsen, or recur, additional evaluation may be needed to check for complications such as abscess formation or to consider alternative diagnoses.

What Are the Possible Complications of Orchitis?

Complications of orchitis include testicular atrophy (shrinkage), testicular abscess requiring drainage, and potential fertility problems (especially with bilateral mumps orchitis). Chronic pain can occasionally persist. With prompt and proper treatment, most bacterial orchitis cases resolve without long-term consequences.

While most cases of orchitis resolve with appropriate treatment, understanding potential complications helps patients recognize warning signs that require additional medical attention. The risk of complications varies depending on the cause, whether one or both testicles are affected, and how promptly treatment is initiated.

Testicular Atrophy

Testicular atrophy (shrinkage of the affected testicle) is one of the more common complications, occurring in approximately 30-50% of mumps orchitis cases. The inflammatory process can damage the seminiferous tubules (the structures where sperm are produced), leading to reduced testicular size over weeks to months following the infection. Some degree of atrophy may be permanent.

Bacterial orchitis, when properly treated, less commonly results in atrophy. However, delayed treatment or inadequate antibiotic therapy increases this risk. The atrophy itself is usually not painful, but it can affect sperm production from that testicle.

Fertility Implications

The effect of orchitis on fertility depends primarily on whether one or both testicles are involved. Unilateral orchitis (affecting only one testicle) rarely causes significant fertility problems because the unaffected testicle typically compensates and produces adequate sperm. Even if the affected testicle has reduced function, a single healthy testicle usually maintains normal fertility.

Bilateral orchitis (affecting both testicles), particularly from mumps, carries a higher risk of fertility impairment. Studies suggest that bilateral mumps orchitis can cause reduced sperm counts or, in severe cases, azoospermia (complete absence of sperm) in some men. However, complete sterility is uncommon even after bilateral involvement. Men who have had mumps orchitis and are concerned about fertility can have a semen analysis performed to assess sperm count and quality.

Testicular Abscess

A testicular abscess is a collection of pus within the testicle or surrounding tissues that can develop if bacterial orchitis is not adequately treated or if particularly virulent organisms are involved. Signs suggesting abscess formation include failure to improve with antibiotics, a fluctuant (fluid-filled) swelling on examination, and persistent fever despite treatment.

Abscesses typically require surgical drainage in addition to antibiotic therapy. In severe cases where the testicle is destroyed by infection, orchiectomy (surgical removal of the testicle) may be necessary, though this is rare with modern treatment.

Chronic Epididymo-Orchitis

Some men develop chronic pain or discomfort in the affected testicle that persists for months after the acute infection has resolved. This chronic epididymo-orchitis can be challenging to treat and may require prolonged courses of anti-inflammatory medications, physical therapy, or in refractory cases, surgical intervention.

Frequently Asked Questions About Orchitis