Pathophysiology of lower urinary tract symptoms in the aging male population.

Nearly all men will develop histological benign prostatic hyperplasia by the age of 80, but the degree of prostatic enlargement resulting from the hyperplasia is highly variable. Historically, it has often been assumed that the pathophysiology of lower urinary tract symptoms (LUTS) in men is the result of bladder outlet obstruction associated with prostatic enlargement. The observation that prostatic enlargement, bladder outlet obstruction, and LUTS are all age-dependent has been interpreted to indicate that these phenomena were causally related, but there is insufficient evidence for this. Undoubtedly, some men's prostatic enlargement causes obstruction and symptoms. Based on the available data, however, this subset appears to be extremely small. Because of the many urological and nonurological conditions that cause LUTS and age-dependent changes in bladder and neurological function, it is unlikely that there exists a single dominant etiology for the aging male population. If this is the case, then the optimal management of LUTS will require different and possibly combination therapies.