Prostatitis is a common clinical problem and can be due to infectious or noninfectious etiologies. Data from the U.S. National Center for Health Statistics and other sources, including population-based studies, suggest that nearly 9% of the male population suffer from prostatitis and pelvic pain symptoms and that there are more than 2 million physician's visits annually for prostatitis, most of which are to internists and family practitioners.

Prostatitis is thought to represent the clinical syndrome correlating with inflammatory exudate within the ducts and prostate gland tissue. In acute prostatitis, the inflammatory cells are polymorphonuclear (PMN) leukocytes. In chronic prostatitis, a lymphocytic and mononuclear inflammatory process is present. Chronic prostatitis is often focal. Furthermore, noninfectious events may contribute to the chronic prostatitis syndrome. For example, prostatic concretions may serve as a nidus for the development of chronic bacterial prostatitis. Focal prostatic necrosis (as part of 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. Although largescale formal epidemiologic studies have not been done, prostatitis not surprisingly is seen most commonly in older men. Bacterial prostatitis is more common in patients with previous prostate disease, diabetes mellitus, and a history of urethral instrumentation (such as catheterization).

Because urethritis is the initial symptom of gonococcal and chlamydial infection, patients seek care early, and with the widespread availability of effective treatments, they are eradicated.