**4. BPH physiopathology, disease progression and renal failure**

The exact etiology of BPH is unknown, however the similarity between BPH and the embryonic morphogenesis of the prostate has led to hypothesis that BPH may result from a reawakening of embryonic induction process in adulthood (Oesterling 1996; McVary 2006).

The most common renal pathology finding in men with obstructive nephropathy due to BPH is chronic interstitial nephritis (Coroneos, Assouad et al. 1997; Rule, Lieber et al. 2005) and 30% of cases have been attributed to obstructive uropathy.

Late or end stage renal failure secondary to prostatic or bladder outflow obstruction should be amenable to prevention if cases are recognised early, however it still difficult to recognise which men with BPH are at risk of renal failure and need close investigation. For this reason we truly believe that is important to recognize factors that can be measured and are important bases or risk factors for the evaluation and treatment of BPH.

To assess BPH as risk factor for chronic kidney disease or renal failure it is important to understand the surrogate measures often used to diagnose BPH. These factors are essentially clinical, anatomical and physiological.
