The epidemiology page lists various factors that have been associated with the risk of prostatitis, e.g. sexual abuse. Risk factors are useful at the bedside because they help to target diagnostic resources to patients more likely to have illness. For example, we know that the risk of prostate cancer increases with age. This knowledge allows us to more closely watch older men than younger men for the development of prostate cancer.
The identification of epidemiological risk factors also allows us to develop conceptual models of causality. So knowing that sexual abuse is a risk factor for prostatitis can help to develop psychosocial models that may lead to psychosocial interventions that may relieve prostatitis symptoms.
Risk factors are not necessarily, but may be, causes of illness. Thus, age in itself, which marks the increased risk of prostate cancer, does not cause prostate cancer. Likewise, risk factors are not necessarily reversible and thus may not be useful as a target for treatments. For example, black race is a risk factor for prostate cancer, but race cannot be changed and is not useful as a target for treatment. Black race is useful solely as a marker of risk.
Apart from identifying risk factors as a means of better surveying and diagnosing patients at risk for specific illness, it becomes very important to identify the actual cause of an illness. So it is not enough to identify that age is a risk factor for heart attack. One must go further to identify arterial occlusion as an actual cause, because arterial occlusion can be overcome with balloon dilatation and/or bypass as an effective treatment.
So what are the causes of prostatitis?
The causes of acute prostatitis are almost always infectious. It is most commonly caused by bacteria, such as common E coli and Pseudomonas aeruginosa. There are also cases of non-bacterial acute prostatitis. For example, one can have fungal prostatitis from such agents as blastomyces and cryptococcus, but these are quite rarely and seem to occur principally in patients who are compromised by such other ongoing illness as HIV infection and/or terminal cancer.
The causes of chronic prostatitis are not clear. Despite the fact that so many are treated as infectious illness with months, if not years, of antibiotics, they are mainly not infectious. There are clues from experimental models, however, that suggest that psychosocial factors as prostatitis causes. For example, upon stressing through such mechanisms as refrigeration and/or sleep deprivation, rats develop prostate inflammation. One has to be careful about over-interpreting such findings for two reasons. First of all, prostate inflammation may be completely asymptomatic, a clinical condition known as type IV prostatitis. Secondly, the relevance of rat illness to human illness is not clear.
Another interesting clue from experimental models is that chemical exposure of parental rats to the agricultural pesticide vinclozolin can result in prostate inflammation of their offspring. We are aware of no data in humans that suggests that prostatitis is somehow caused by exposure of one's parents to chemicals.