Obstructive uropathy in the male.

BPH is not synonymous with prostatic obstruction. The cause of symptoms in men with prostatism is multifactorial, comprising four conditions: (1) prostatic urethral obstruction, (2) impaired detrusor contractility, (3) detrusor instability, and (4) sensory urgency. Some men have an isolated obstruction at the vesical neck, termed primary vesical neck obstruction, that may have a different cause from that of BPH, and others have a learned voiding dysfunction wherein they are unable to relax completely during micturition. There is no simple means of distinguishing the various conditions that underlie voiding symptoms in men. Neither simple cystometry nor uroflow suffice. Detrusor pressure and uroflow studies usually are definitive, but more sophisticated analysis may be necessary.