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Best tests for Epididymitis

Written by Andrew Le, MD.
Last updated June 7, 2024

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Epididymitis causes inflammation of the epididymis, a small, coiled tube located at the back of the testicle that stores and transports sperm. It is a relatively common condition that can cause significant discomfort and may lead to complications if left untreated. Accurate diagnosis and appropriate treatment are important for managing epididymitis effectively.

In this article, we will discuss the best tests for diagnosing epididymitis and provide an overview of the condition, including its epidemiology, risk factors, differential diagnosis, treatment approaches, and long-term prognosis.

Epidemiological Factors and Risk Profiles for Epididymitis

Epididymitis is a relatively common condition, with an estimated 600,000 cases occurring annually in the United States.9,11 The condition can affect men of all ages, but typically is caused by different bacteria in age groups 14-35 and 35+.10,11 In the younger age group, epididymitis is often caused by sexually transmitted infections (STIs) such as chlamydia and gonorrhea, while in older men, it is more likely to be caused by urinary tract infections or other bacterial infections.1,3

Many risk factors can increase the likelihood of developing epididymitis. These include sexual activity, particularly with multiple partners or without the use of condoms, as well as urinary tract infections, recent urinary tract surgery or instrumentation, and anatomical abnormalities of the urinary tract.1,2 Certain underlying medical conditions, such as diabetes or immunosuppression, can also increase the risk of epididymitis.1,2

It is important to learn prevention strategies such as safe sex practices as this is a common condition.

Diagnostic Imaging and Laboratory Tests for Epididymitis

Diagnosing epididymitis typically involves a combination of clinical assessment, imaging studies, and laboratory tests. Epididymitis often causes scrotal pain, swelling, and tenderness. These symptoms may be accompanied by urinary symptoms like dysuria (burning, stinging, or itching while urinating) and changed frequency.10,14 However, these symptoms can also be caused by other conditions, such as testicular torsion. Testicular torsion is a medical emergency that requires immediate surgical intervention.10,11

Imaging is important in diagnosing epididymitis and in distinguishing it from other scrotal conditions. Ultrasonography, particularly with color Doppler, can be used to look inside the scrotum.16,17 Ultrasound can help find the characteristic traits of epididymitis, such as an enlarged, hypoechoic (appearing darker on the scan) epididymis with increased blood flow, and can also rule out other conditions like testicular torsion or testicular masses.16,17

Laboratory tests are also an important part of the diagnostic process for epididymitis. Urinalysis and urine culture can help identify urinary tract infections and help your healthcare provider choose the right antibiotic.18,19 In sexually active men, testing for STIs such as chlamydia and gonorrhea is recommended, as these are common causes of epididymitis in this population.18,19 Nucleic acid amplification tests (NAATs) on urine or urethral swab samples are commonly used to detect these infections.19

Differential Diagnosis and Distinguishing Epididymitis From Other Scrotal Conditions

One of the challenges in diagnosing epididymitis is distinguishing it from other conditions that can cause similar symptoms. The most important differential diagnosis is testicular torsion, which is a surgical emergency that occurs when the testicle becomes twisted on its blood supply, leading to ischemia (restricted or reduced blood flow) and potential necrosis.22,23

Unlike epididymitis, which typically has a gradual onset of symptoms, testicular torsion presents with sudden, severe scrotal pain and swelling, often accompanied by nausea and vomiting.22,23 On physical examination, the affected testicle may be high-riding and sit abnormally, and the cremasteric reflex (a reflex triggered by stimulating the inner thigh causing the testicle on the same side to rise) is often absent.23 Fast recognition and surgical intervention are important to save the testicle in cases of torsion.

Other conditions that can mimic epididymitis include scrotal trauma, inguinal hernia, hydrocele, varicocele, and Fournier's gangrene.21,24 Less common causes of scrotal pain and swelling include vasitis (inflammation of the vas deferens), epididymal cysts, and rare infections like tuberculosis or brucellosis.25,26

A thorough diagnostic workup is important to accurately distinguish epididymitis from these other conditions. This typically includes a detailed medical history, physical examination, imaging studies (particularly scrotal ultrasound with Doppler), and laboratory tests such as urinalysis, urine culture, and STI screening.27,28 In some cases, additional imaging like CT or MRI may be necessary.21

Treatment Approaches and Antimicrobial Therapies for Epididymitis

The main goals of treatment for epididymitis are to treat the underlying infection, ease symptoms, prevent complications, and reduce the risk of transmission of STIs to sexual partners.30 The main treatment is antimicrobial therapy, with the specific regimen decided on based on the patient's age, sexual history, and the most likely cause.30,31

For sexually active men under 35 years old, the most common cause of epididymitis is sexually transmitted infections (STIs) such as chlamydia and gonorrhea. In these cases, the Centers for Disease Control and Prevention (CDC) recommends treatment with a single intramuscular dose of ceftriaxone 250 mg in addition to oral doxycycline 100 mg twice daily for 10 days.30 In some cases, azithromycin 1 g orally in a single dose may be substituted for doxycycline.30

In men over 35 years old or those with a history of urinary tract instrumentation, bacteria like E. coli are more likely to be the cause. In these cases, oral fluoroquinolones such as levofloxacin or ofloxacin are typically recommended.31 Treatment is usually 10-14 days, depending on the severity of the infection and the person’s response to therapy.31

If the disease is antibiotic-resistant, alternative antibiotics such as ertapenem or imipenem may be necessary.33,34

In addition to antibiotics, supportive measures such as elevating the scrotum, ice packs, and nonsteroidal anti-inflammatory drugs (NSAIDs) can help alleviate pain and reduce inflammation.30,31 People with epididymitis should also abstain from sexual activity until they and their partners have completed treatment to prevent re-infection.30

Chronic epididymitis, defined as symptoms lasting more than 6 weeks, can be particularly difficult to manage. In these cases, a longer course of antibiotics (4-6 weeks) may be recommended, along with other treatments such as spermatic cord block, physical therapy, or surgical removal of the epididymis (epididymectomy).30,32 For those with chronic or recurrent epididymitis, consultation with a urologist is often recommended.

In addition to education, public health measures such as screening for sexually transmitted infections, partner notification and treatment, and promotion of safe sex practices can help reduce the incidence and impact of epididymitis.43


Epididymitis is a common condition that can cause significant discomfort and may lead to serious complications if not properly diagnosed and treated. Throughout this comprehensive guide, we have explored the various aspects of epididymitis, including its epidemiology, risk factors, diagnostic approaches, differential diagnosis, treatment strategies, and long-term prognosis.

Accurate diagnosis is important to effectively manage epididymitis, and a combination of clinical assessment, imaging studies, and laboratory tests can help differentiate this condition from other scrotal issues. Starting antibiotics quickly, based on the patient's age, sexual history, and suspected causative organism, is important for treating the infection and preventing complications.


<1>Shigemura K, Kitagawa K, Nomi M, Yanagiuchi A, Sengoku A, Fujisawa M. Risk factors for febrile genito-urinary infection in the catheterized patients by with spinal cord injury-associated chronic neurogenic lower urinary tract dysfunction evaluated by urodynamic study and cystography: a retrospective study. World J Urol. 2020 Mar;38(3):733-740. [PubMed: 30949801]</1>

<2>Agrawal V, Ranjan R. Scrotal abscess consequent on syphilitic epididymo-orchitis.</2>

<3>Thind P., Gerstenberg T.C., Bilde T. Is micturition disorder a pathogenic factor in acute epididymitis? An evaluation of simultaneous bladder pressure and urine flow in men with previous acute epididymitis. J. Urol. 1990;143:323–325. [PubMed] [Google Scholar]</3>

<4>Alzahrani MA, Alkhani KO, Alassaf AM, Alorainy JI, Binsaleh S, Almannie R. Updates in the pathophysiology of COVID-19 infection in male reproductive and sexual health: a literature review. Andrologia. 2022 Aug;54(7):e14388. doi: 10.1111/and.14388. Epub 2022 May 10. PMID: 35537270.</4>

<5>Centers for Disease Control and Prevention. (2021). Sexually Transmitted Infections Treatment Guidelines, 2021. Retrieved from</5>

<6>Cleveland Clinic. (n.d.). Epididymitis: Causes, Symptoms, Diagnosis & Treatment. Retrieved from</6>

<7>Healthline. (2020). Epididymitis: Symptoms, Causes, Treatment, and More. Retrieved from</7>

<8>Carneiro A, Sillero R, Fraga A, Sampaio L, Almeida R, Pereira A, Palma P, Figueiredo A. Radiological patterns of incidental epididymitis in mild-to-moderate COVID-19 patients revealed by colour Doppler ultrasound. Andrologia. 2021 Aug;53(7):e14013. doi: 10.1111/and.14013. Epub 2021 Apr 26. PMID: 33904159; PMCID: PMC7994978.</8>

<9>Epididymitis | Clinical Infectious Diseases | Oxford Academic. (n.d.). Retrieved from</9>

<10>Epididymitis - StatPearls - NCBI Bookshelf. (n.d.). Retrieved from</10>

<11>Epididymitis: Practice Essentials, Anatomy, Etiology. (n.d.). Retrieved from</11>

<12>Inhibition of adhesion and fibrosis after epididymectomy for chronic epididymitis improves pain relief, according to a study of 43 patients who still had pain despite conservative treatment. (n.d.). Retrieved from</12>

<13>It has been found that epididymectomy may be more effective in men post vasectomy compared with those who have not undergone vasectomy. (n.d.). Retrieved from</13>

<14>Antibiotic Therapy for Epididymitis. (n.d.). Retrieved from</14>

<15>What are the CDC guidelines for treatment of acute ...? (n.d.). Retrieved from</15>

<16>Dogra, V. S. (n.d.). Epididymitis Imaging: Practice Essentials, Ultrasonography, Magnetic resonance imaging (MRI). Medscape.</16>

<17>Epididymitis | Radiology Reference Article | (n.d.).</17>

<18>Epididymitis Diagnosis. (n.d.).</18>

<19>Epididymitis - STI Treatment Guidelines. (n.d.). Centers for Disease Control and Prevention.</19>

<20>Yusuf, G., Sellars, M. E., Kooiman, G. G., Diaz-Cano, S., & Sidhu, P. S. (2013). Global testicular infarction in the presence of epididymitis: clinical features, appearances on grayscale, color Doppler, and contrast-enhanced sonography, and histologic correlation. Journal of Ultrasound in Medicine, 32(1), 175-180.</20>

<21>Sieger N, Di Quilio F, Stolzenburg JU. What is beyond testicular torsion and epididymitis? Rare differential diagnoses of acute scrotal pain in adults: A systematic review. Ann Med Surg (Lond). 2020 Jul. 55:265-274. [QxMD MEDLINE Link]. [Full Text].</21>

<22>Lorenzo L, Rogel R, Sanchez-Gonzalez JV, Perez-Ardavin J, Moreno E, Lujan S, et al. Evaluation of Adult Acute Scrotum in the Emergency Room: Clinical Characteristics, Diagnosis, Management, and Costs. Urology. 2016 Aug. 94:36-41. [QxMD MEDLINE Link].</22>

<23>Siegel A, Snyder H, Duckett JW. Epididymitis in infants and boys: underlying urogenital anomalies and efficacy of imaging modalities.</23>

<24>Starostin, D., Ibrahim, M., & Ahmed, N. (2023). A case of post-HoLEP vasitis mimicking incarcerated inguinal hernia. A diagnostic approach. Urology Case Reports, 45, 102243.</24>

<25>Zhang, T., Chu, L., Tan, W., Ye, C., & Dong, H. (2022). Human epididymis protein 4, a novel potential biomarker for diagnostic and prognosis monitoring of lung cancer. Frontiers in Oncology, 12, 1023688.</25>

<26>Salif, A., Bigirimana, F., Willems, S., Reichman, G., Noels, J., Van Den Wijngaert, S., ... & Clevenbergh, P. (2022). Bacillus Calmette-Guérin (BCG) prostato-epididymitis in a patient treated for a non-invasive urothelial cancer: A case report. Urology Case Reports, 43, 102102.</26>

<27>Sosnowska-Sienkiewicz, P., Januszkiewicz-Lewandowska, D., & Mańkowski, P. (2022). Testicular and scrotal abnormalities in pediatric and adult patients. Journal of Ultrasonography, 22(91), 231-239.</27>

<28>Barbosa, R. G., Favorito, L. A., & Sampaio, F. J. B. (2022). Morphometric study applied to testicular and epididymis hydatids torsion. International braz j urol, 48(5), 1021-1030.</28>

<29>Yu KJ, Wang TM, Chen HW, Wang HH. The dilemma in the diagnosis of acute scrotum: clinical clues for differentiating between testicular torsion and epididymo-orchitis. Chang Gung Med J. 2012 Jan-Feb. 35(1):38-45. [QxMD MEDLINE Link].</29>

<30>Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People · Sexually Transmitted Infections Treatment Guidelines, 2021 ... Acute epididymitis is a clinical syndrome causing pain, swelling, and inflammation of the epididymis and lasting <6 weeks (1191).</30>

<31>Louette A, Krahn J, Caine V, Ha S, Lau TTY, Singh AE. Treatment of Acute Epididymitis: A Systematic Review and Discussion of the Implications for Treatment Based on Etiology. Sex Transm Dis. 2018 Dec;45(12):e104-e108. [PubMed: 30044339]</31>

<32>Davis BE, Noble MJ, Weigel JW, Foret JD, Mebust WK. Analysis and management of chronic testicular pain. J Urol. 1990 May;143(5):936-9. [PubMed: 2329604]</32>

<33>Falagas ME, Karageorgopoulos DE. Extended-spectrum beta-lactamase-producing organisms. J Hosp Infect. 2009; 73:345–54.</33>

<34>Hoban DJ, Lascols C, Nicolle LE, Badal R, Bouchillon S, Hackel M, et al. Antimicrobial susceptibility of Enterobacteriaceae, including molecular characterization of extended-spectrum beta-lactamase-producing species, in urinary tract isolates from hospitalized patients in North America and Europe: results from the SMART study 2009-2010.</34>

<35>Lorenzo, L., Rogel, R., Sanchez-Gonzalez, J. V., Perez-Ardavin, J., Moreno, E., Lujan, S., ... & Fernandez, A. (2016). Evaluation of Adult Acute Scrotum in the Emergency Room: Clinical Characteristics, Diagnosis, Management, and Costs. Urology, 94, 36-41.</35>

<36>Lampejo T, Abdulcadir M, Day S. Retrospective review of the management of epididymo-orchitis in a London-based level 3 sexual health clinic: an audit of clinical practice. Int J STD AIDS. 2017 Sep;28(10):1038-1040. [PubMed: 28201951]</36>

<37>Padmore and colleagues18 described a series of 27 men who underwent epididymectomy after empiric long-term and repeated courses of antibiotics and/or anti-inflammatory agents had failed, and reported patient satisfaction to be extremely high in the epididymal cyst group compared with the epididymitis/epididymalgia group (92% vs 43%).</37>

<38>Of the 16 patients, 14 were reported to have excellent initial symptomatic benefit from epididymectomy. Long-term follow-up in 10 patients suggested that the benefits were durable. Poor outcome was predicted in patients with atypical symptoms, including testicular or groin pain, erectile dysfunction, and normal appearance of the epididymis on ultrasound.</38>

<39>Many patients with chronic epididymitis also have associated testicular pain. Chronic testicular pain, or "chronic orchalgia," has been defined as "intermittent or constant testicular pain three months or longer in duration that significantly interferes with the daily activities of the patient so as to prompt him to seek medical attention."1 In many cases, however, the patient will present with epididymal pain and discomfort only, particularly in the chronic stage of the condition.</39>

<40>Grygiel-Górniak, B., & Folga, B. A. (2022). Chronic epididymitis and Grade III varicocele and their associations with semen characteristics in men consulting for couple infertility. Andrologia, 54(1), e14235.</40>

<41>Agrawal, V., & Ranjan, R. (2015). Scrotal abscess consequent on syphilitic epididymo-orchitis. Canadian Urological Association Journal, 9(3-4), E148-E151.</41>

<42>Kraft, K. H., Raheem, O. A., & McAninch, J. W. (2016). Orchitis: Epidemiology, diagnosis, and treatment. Urologic Clinics of North America, 43(1), 101-111.</42>

<43>Shigemura, K., Kitagawa, K., Nomi, M., Yanagiuchi, A., Sengoku, A., & Fujisawa, M. (2020). Risk factors for febrile genito-urinary infection in the catheterized patients by with spinal cord injury-associated chronic neurogenic lower urinary tract dysfunction evaluated by urodynamic study and cystography: a retrospective study. World Journal of Urology, 38(3), 733-740.</43>

<44>Davis, B. E., Noble, K. J., & Weigel, J. W. (1990). Analysis and management of chronic testicular pain. The Journal of Urology, 143(5), 936-939.</44>

<45>Nickel, J. C., Siemens, D. R., Nickel, K. R., & Downey, J. (2002). The patient with chronic epididymitis: characterization of an enigmatic syndrome. The Journal of Urology, 167(4), 1701-1704.</45>

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Dr. Le obtained his MD from Harvard Medical School and his BA from Harvard College. Before Buoy, his research focused on glioblastoma, a deadly form of brain cancer. Outside of work, Dr. Le enjoys cooking and struggling to run up-and-down the floor in an adult basketball league.

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