An Overview of Epididymitis

Painful inflammation in the testicles is mostly caused by STDs

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Epididymitis is the inflammation of the epididymis, the coiled tube at the back of the testicle that stores and carries sperm. Epididymitis is recognized by pain, redness, and swelling, usually in one testicle only. Boys and men ages 14 to 35 are the most affected. Bacterial infections are the predominant cause of epididymitis, especially sexually transmitted infections like chlamydia and gonorrhea.

Epididymitis is diagnosed based on a review of symptoms along with blood tests, bacterial cultures, and ultrasound to identify the underlying cause. Antibiotics are the mainstay of treatment, the choice of which is based on the bacteria involved.


Epididymitis is most often acute, meaning that the onset and duration of symptoms are rapid (under six weeks). Chronic epididymitis can also occur with symptoms persisting for over 12 weeks and in excess of five years in some cases.

Acute Epididymitis

Acute epididymitis tends to develop over several days with the pain, redness, swelling, and warmth typically limited to one testicle only. The scrotum of the affected testicle will often hang lower. The epididymis itself will feel significantly thicker and firm.

There may be a visible discharge from the opening of the penis (urethra) and pain or burning when urinating. Fever and sore throat are also common.

Chronic Epididymitis

Chronic epididymitis may manifest with persistent tenderness and discomfort, although the actual swelling of the epididymis can come and go. The pain will often radiate to the groin, thigh, and lower back. Sitting for prolonged periods can make it worse.

The persistent inflammation associated with chronic epididymitis can "spill over" to the prostate, leading to discomfort in the groin and perineum (the area between the scrotum and anus) as well as difficulty urinating.


If left untreated, acute epididymitis can lead to major complications, including the development of testicular abscesses and necrosis (tissue death). Chronic epididymitis may cause permanent obstruction of the epididymis, leading to reduced fertility and hypogonadism (low testosterone levels).

In some cases, the underlying infection can spread to other organs. Men with benign prostatic hyperplasia (enlarged prostate) may experience a worsening of symptoms as the result of epididymal inflammation.


Epididymitis is not a disease but rather the consequence of a disease. Though urinary tract infections (UTIs) are rare in men, bacterial infections are the most common cause of acute epididymitis. In sexually active men, chlamydia (Chlamydia trachomatis) represents the bulk of epididymal infections, followed by gonorrhea (Neisseria gonorrhoeae).

Escherichia coli (E. coli) is a common cause of epididymitis that is not sexually transmitted (although infection can occur as the result of anal sex).

E. coli is considered a likely cause of epididymitis in young boys, elderly men, and men who have sex with men (MSM). Men with HIV can develop epididymitis as a result of opportunistic infections like ureaplasma, mycobacterium, cytomegalovirus, or cryptococcus.

Non-Infectious Causes

There are also non-infectious causes of epididymitis. These include the reflux (backflow) of urine into the vas deferens (the tube that carries semen to the urethra). Any form of genital or urinary tract surgery can cause epididymitis, as can the drug amiodarone use to treat heart rhythm disorders.

Younger boys can develop epididymitis as a result of enterovirus, adenovirus, or Mycoplasma pneumonia.

Less commonly, epididymitis may be a side effect of sarcoidosis (a disease characterized by hardened granulomas). Black men with Behçet's disease, an autoimmune disorder, are also prone to epididymitis.


Epididymitis can be diagnosed with a review of symptoms and medical history. The physical exam would look for signs of redness, swelling, tenderness, and warmth occurring unilaterally (on one side only).

The doctor may also check for signs of discharge, often revealed by gentle milking the penis with gloved hands. If chlamydia or gonorrhea is suspected, the doctor will take a swab of the discharge and send it to the lab for evaluation. Blood and urine tests may also be ordered to identify other causes.

If the cause of the epididymitis is unclear or the symptoms are unusual, the doctor may order a Doppler ultrasound to visualize the epididymis and evaluate blood flow to the affected area.

Differential Diagnoses

Other conditions that mimic epididymitis include testicular torsion (twisted testicle), inguinal hernia, infected hydroceles, and testicular cancer. To ensure the correct treatment, the doctor may want to perform a differential diagnosis to exclude other possible causes.

To differentiate epididymitis from testicular torsion, the doctor may test the cremasteric reflex (in which the testicle rises when the inner thigh is stroked). A positive cremasteric reflex generally excludes testicular torsion as a cause. There would also be a positive Prehn sign, in which pain persists even when the scrotum is lifted.

A Doppler ultrasound is the most effective way to differentiate epididymitis from an inguinal hernia, hydroceles, and testicular cancer.


The prompt treatment of epididymitis is essential to resolving the underlying infection, avoiding testicular damage, and preventing the transmission of a sexually transmitted disease.

Both acute and chronic epididymitis are treated with antibiotics. Azithromycin, ceftriaxone, and doxycycline are the antibiotics of choice for chlamydia and gonorrhea. Cefixime, erythromycin, levofloxacin, or ofloxacin can be used as alternatives or to treat other types of infection.

Quinolone antibiotics are no longer used to treat gonorrhea due to the widespread resistance of N. gonorrhoeae to this class of drugs.

The choice of antibiotic can vary based on the underlying cause and whether the condition is acute or chronic:

  • Chlamydia may be treated with a single 1-gram (g) dose of azithromycin or a daily 100-milligram (mg) dose of doxycycline for up to seven days.
  • Gonorrhea may be treated with a single 250-mg intramuscular injection of ceftriaxone or a single 1-g oral dose of azithromycin.
  • E. coli infections can be treated with a seven- to 14-day course of oral levofloxacin or ofloxacin.
  • Chronic epididymitis may require a four- to six-week course of azithromycin or ceftriaxone to ensure clearance of the infection.
  • Epididymitis in children is most often the result of a UTI and is best treated with co-trimoxazole or penicillin.

Generally speaking, you would expect to experience relief from acute epididymitis within 48 to 72 hours of starting an antibiotic. Relief from chronic epididymitis will likely take longer.

You must complete the entire course of antibiotics even if your symptoms have resolved. The premature discontinuation can lead to antibiotic resistance, making it far more difficult to treat a bacterial infection should one return.

Resting, taking warm tub soaks, applying ice packs, and supporting the scrotum with an athletic supporter can relieve discomfort. Tylenol (acetaminophen) or an over-the-counter nonsteroidal anti-inflammatory drug (NSAID) like ibuprofen or naproxen can also help.

A Word From Verywell

If you are diagnosed with gonorrhea or chlamydia, it is important to inform your sexual partners so that they can seek treatment. If you have had sexual contact within 60 days of the appearance of symptoms, then you are likely to have passed the infection to others.

To avoid further transmission, avoid having sex until the infection is confirmed cured.

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  1. Taylor SN. Epididymitis. Clin Infect Dis. 2015 Dec;61(Suppl 8):S770-S773. doi:10.1093/cid/civ812

  2. Kavoussi PK, Costabile, RA, Salonia A (2013). "Disorders of scrotal contents: orchitis, epididymitis, testicular torsion, torsion of the appendages, and Fournier's gangrene." In Chapple CR, Steers WD (eds). Clinical Urologic Endocrinology: Principles for Men’s Health. London: Springer-Verlag.

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