[Physiopathology of BPH obstruction].

The underlying BPH related mechanisms of outlet obstruction are outlined (modification of the shape of the bladder neck, failure of funnel formation, geometric variations of the urethra, alpha 1 adrenoceptors mediated sympathetic hyperactivity at the level of the lower genito-urinary tract). Bladder voiding dysfunction in response to prostate obstruction is also discussed and correlated to ultrastructural patterns and clinical symptoms. Finally, a pathogenetic mechanism for detrusor overactivity in obstructed bladder is suggested.