Bacterial prostatitis is an infection of the prostate gland caused by bacteria that leads to inflammation, pain, and urinary problems. While it represents only a small portion of all prostatitis cases, bacterial prostatitis requires prompt medical attention and proper treatment with antibiotics to prevent serious complications.

How Common Is Bacterial Prostatitis

Bacterial prostatitis is relatively uncommon compared to other prostate conditions. While more than 2 million men visit healthcare providers each year for prostatitis symptoms, bacterial forms account for only a small fraction of these cases^[1]. Up to 50 percent of men will experience symptoms of some form of prostatitis at some point in their lives, making it the most common urinary tract issue in men under 50 and the third most common in men over 50^[1].

Acute bacterial prostatitis is estimated to comprise approximately 10 percent of all prostatitis diagnoses^[5]. The condition shows a bimodal distribution, meaning it tends to affect two distinct age groups: younger men between 20 and 40 years of age, and older men over 70 years^[4][5]. After an episode of acute bacterial prostatitis, approximately 5 percent of patients may go on to develop chronic bacterial prostatitis^[6].

The exact incidence and prevalence of acute bacterial prostatitis remain unknown, though prostatitis-like symptoms combined have a prevalence of 8.2 percent in men^[5]. The lifetime prevalence of chronic prostatitis ranges from 1.8 to 8.2 percent, and may be even higher in some populations^[17]. Most cases are community-acquired, meaning they develop outside of hospitals, though some occur after medical procedures. In fact, community-acquired infections are three times more common than infections that develop in healthcare settings^[5].

What Causes Bacterial Prostatitis

Bacterial prostatitis develops when bacteria infect the prostate gland. The prostate sits below the bladder, in front of the rectum, and surrounds the urethra, which is the tube that carries urine and semen out of the body^[1]. Any bacteria capable of causing a urinary tract infection can potentially cause acute bacterial prostatitis^[3].

The most common culprit is Escherichia coli, often called E. coli, which is a bacterium that normally lives in the colon. This organism is responsible for the majority of cases, accounting for approximately 50 to 90 percent of bacterial prostatitis infections^[4][5]. Other common bacterial causes include Pseudomonas aeruginosa, and species of Klebsiella, Enterococcus, Enterobacter, Proteus, and Serratia^[4][5].

In sexually active younger men, infections spread through sexual contact can cause prostatitis. These include bacteria such as Neisseria gonorrhoeae (which causes gonorrhea), Chlamydia trachomatis (which causes chlamydia), and Ureaplasma urealyticum^[4]. Gram-positive organisms such as Enterococcus species and Staphylococcus species are also sometimes responsible for the infection^[4].

Most cases of acute bacterial prostatitis occur when bacteria travel up through the urethra or when urine containing bacteria flows backward into the prostate, a process called intraprostatic reflux^[5]. Less commonly, bacteria may spread directly from the rectum or through the lymphatic system, or they may reach the prostate through the bloodstream during a bacterial infection elsewhere in the body^[5].

Bacterial prostatitis may also develop after medical procedures that manipulate the prostate or urinary tract. These include transrectal prostate biopsy, transurethral surgery, urethral catheterization, and cystoscopy^[5]. Prostate manipulation from such procedures increases the risk of developing infections with bacteria like Pseudomonas, mixed organisms, and staphylococcal species^[4].

Risk Factors for Bacterial Prostatitis

Certain conditions and behaviors increase the likelihood of developing bacterial prostatitis. Men over 50 years of age who have an enlarged prostate face a higher risk because the prostate gland may become blocked, making it easier for bacteria to grow^[3]. Benign prostatic hypertrophy, which is non-cancerous enlargement of the prostate, is a significant risk factor for the condition^[5].

Other genitourinary infections increase the risk of developing prostatitis. These include epididymitis (inflammation of the tube at the back of the testicle), orchitis (inflammation of the testicle), urethritis (inflammation of the urethra), and urinary tract infections^[5]. When bacteria from these infections spread to the prostate, they can trigger prostatitis.

Sexual practices and history also play a role. High-risk sexual behavior, having many sexual partners, and a history of sexually transmitted diseases all increase the risk of developing bacterial prostatitis^[5]. Certain sexual practices, such as having anal sex without wearing a condom, are more likely to lead to infections that can cause prostatitis^[3].

Medical procedures involving the prostate or urinary tract represent another category of risk factors. These include cystoscopy (examination of the bladder with a camera), transrectal prostate biopsy (removing prostate tissue through the rectum), transurethral surgery (procedures through the urethra), urethral catheterization (placing a tube in the urethra to drain urine), and urodynamic studies (tests of bladder function)^[5].

Additional risk factors include phimosis, which is a condition where the foreskin of the penis cannot be pulled back, and injuries to the area between the scrotum and anus, called the perineum^[3][5]. Problems with the urethra or prostate, such as blockages that reduce or prevent the flow of urine out of the bladder, or urethral stricture (narrowing of the urethra), also increase susceptibility^[3][5].

Being immunocompromised significantly raises the risk of bacterial prostatitis, particularly from unusual organisms^[4]. Acute bacterial prostatitis is rare in general, but when it does occur, it is often associated with bladder outlet obstruction or an immunocompromised state^[4].

Symptoms of Bacterial Prostatitis

The symptoms of bacterial prostatitis depend on whether the condition is acute or chronic. Acute bacterial prostatitis comes on suddenly and causes severe symptoms that require immediate medical attention^[1]. In contrast, chronic bacterial prostatitis develops gradually, and symptoms are generally less severe but last longer^[1].

Men with acute bacterial prostatitis typically experience flu-like symptoms including fever, body aches, and chills^[1][3]. These systemic symptoms signal that the infection is serious and spreading. Additional symptoms may include flushing of the skin and lower stomach tenderness^[3]. The condition causes painful or burning sensations during urination, a symptom called dysuria^[2][5].

Urinary symptoms are prominent in both acute and chronic bacterial prostatitis. Men often experience difficulty starting to urinate or emptying the bladder completely^[3]. The urine stream may be weak or may stop and start^[1][3]. There is frequently an urgent need to urinate, and this urge may occur more often at night, a condition called nocturia^[2][3].

Pain is a central feature of bacterial prostatitis. Affected men typically feel pain or aching in the lower abdomen, particularly above the pubic bone, or in the genitals^[1][3]. The pain may spread to the lower back, groin, or the area between the scrotum and rectum called the perineum^[1][2]. Some men experience pain in the testicles^[3].

Sexual function may also be affected. Men with bacterial prostatitis may experience pain during ejaculation or blood in the semen, a condition called hematospermia^[1][3]. Pain during sexual intercourse, termed dyspareunia, is another possible symptom^[1]. Some men develop erectile dysfunction as a result of the condition^[1].

Blood may appear in the urine, a condition known as hematuria, and the urine may appear cloudy or have a foul smell^[1][2][3]. In acute bacterial prostatitis, the swollen prostate gland may block the flow of urine, making it difficult or impossible to urinate voluntarily^[5]. When this happens, it becomes a medical emergency requiring immediate treatment.

Chronic bacterial prostatitis presents with similar symptoms, but they develop more gradually and are less severe than in the acute form^[1]. Unlike acute bacterial prostatitis, the chronic form usually does not cause fever and chills^[1]. Symptoms may come and go over time, and some people have no symptoms between episodes of prostatitis^[3]. Men with chronic bacterial prostatitis often experience relapsing urinary tract infections with the same bacteria identified repeatedly^[6].

If prostatitis occurs together with an infection in or around the testicles, such as epididymitis or orchitis, additional symptoms specific to those conditions may develop^[3]. Pain with bowel movements is another symptom that some men experience^[3].

Prevention of Bacterial Prostatitis

While bacterial prostatitis cannot always be prevented, certain measures may reduce the risk of developing this condition. The risk of bacterial prostatitis that develops after medical procedures can be reduced by using antibiotics before certain procedures. For example, taking antibiotics such as ciprofloxacin before a transrectal prostate biopsy can help prevent nosocomial bacterial prostatitis^[5][7].

Practicing safer sexual behaviors helps prevent infections that can lead to prostatitis. This includes using condoms during sexual activity, particularly during anal sex, and reducing the number of sexual partners^[3][5]. Seeking prompt treatment for sexually transmitted infections also reduces the risk of these infections spreading to the prostate.

For men with urinary tract infections or other genitourinary infections such as epididymitis, orchitis, or urethritis, getting proper and complete treatment can help prevent bacteria from spreading to the prostate^[5]. Men who require urinary catheters or undergo procedures like cystoscopy should follow their healthcare provider’s instructions carefully to minimize infection risk.

Maintaining good urinary health may also help. This includes urinating often and completely, avoiding holding urine for long periods, and staying well-hydrated^[15]. Men with conditions that can lead to blockage of urine flow, such as benign prostatic hypertrophy or urethral stricture, should work with their healthcare providers to manage these conditions effectively.

How Bacterial Prostatitis Affects the Body

Bacterial prostatitis causes inflammation and swelling of the prostate gland. When bacteria infect the prostate, the tissue in and around this walnut-sized gland becomes swollen, tender, and irritated^[1]. The prostate, which normally produces fluid that becomes part of semen, cannot function properly when inflamed^[2].

Because the prostate surrounds the urethra at the neck of the bladder, swelling of the prostate can compress the urethra and interfere with the normal flow of urine^[1][2]. This compression explains many of the urinary symptoms experienced by men with bacterial prostatitis, including difficulty starting urination, weak urine stream, and the inability to empty the bladder completely. In severe cases, acute inflammation can cause the prostate to swell so much that it completely blocks urinary outflow from the bladder, creating a medical emergency^[16].

The infection triggers an immune response in the prostate tissue, leading to an influx of white blood cells called leukocytes that try to fight the bacteria. This immune response causes further inflammation and the release of chemicals that contribute to pain and discomfort^[6]. The inflamed and swollen prostate becomes tender to the touch, which is why a digital rectal examination, where a healthcare provider gently presses on the prostate through the rectum, often reveals tenderness in men with acute bacterial prostatitis^[3].

The presence of bacteria and inflammation in the prostate can lead to the appearance of white blood cells, bacteria, and sometimes blood in the urine. Prostatic fluid, which is examined in diagnostic tests, typically shows leukocytosis, which means an increased number of white blood cells representing prostatic inflammation^[6].

In acute bacterial prostatitis, bacteria may enter the bloodstream from the infected prostate, potentially leading to sepsis, a life-threatening condition where the body’s response to infection causes widespread inflammation throughout the body^[5]. This is why acute bacterial prostatitis is considered a medical emergency and why vigorous prostatic massage should be avoided in suspected cases, as it could spread bacteria into the bloodstream^[5][7].

In chronic bacterial prostatitis, the inflammation is less intense but persists over time. The bacteria may reside in areas of the prostate that are difficult for antibiotics to reach, allowing them to survive and cause recurring infections^[12]. The ongoing inflammation can lead to changes in the prostate tissue structure over time, potentially contributing to chronic pain and discomfort.

The impact of bacterial prostatitis extends beyond the prostate itself. Pain signals from the inflamed prostate can affect nearby nerves, causing pain to radiate to the lower back, groin, genitals, and perineum^[2]. The inflammation can also affect sexual function, leading to painful ejaculation and erectile dysfunction. When the infection spreads to nearby structures, it can cause epididymitis or orchitis, adding testicular pain and swelling to the symptoms^[3].