Prostatitis and pelvic pain syndromes in men are a common clinical problem and can be due to infectious or noninfectious etiologies. It is estimated that nearly 9% of the male population suffer from prostatitis and pelvic pain symptoms, and that there are >2 million annual physician visits for prostatitis. Over half of patients presenting with prostatic symptoms get treated with antibiotics at some time.

In acute prostatitis, the acute inflammatory response often involves most if not all of the gland, whereas chronic prostatitis is often focal. Noninfectious pathology may be cofactors. For example, prostatic concretions may be a nidus for infection, and focal prostatic necrosis (benign prostatic hyperplasia) may cause prostatic inflammation, even without infection.

The majority of bacterial prostatitis cases occur due to reflux of infected urine into the prostatic ducts and canaliculi, and these cases are seen most commonly in older men, usually associated with other structural or functional abnormalities of the genitourinary tract. Bacterial prostatitis is more common in patients with previous prostate disease, diabetes mellitus, and a history of urethral instrumentation (such as catheterization).

Since urethritis is the initial symptom of gonococcal and chlamydial infection, patients seek care early, and with the widespread availability of effective treatments, the infections are eradicated. Nevertheless, sexually transmitted diseases (STDs), especially chlamydia, have been increasing implicated in a small proportion of cases, usually men < 35 years old. STD-associated chronic prostatitis is rare. Prostatitis due to hematogenously disseminated organisms is unusual and is seen either in immunocompromised hosts or malignancy, and can be caused by Mycobacterium tuberculosis, Cryptococcus neoformans, Coccidioides immitis, Histoplasma capsulatum Aspergillus spp. and Candida.