Urinary tract infections are one very troublesome
complication of an obstructing benign prostatic hyperplasia that can cause patients significant
symptoms. There are two main ways in which BPH cause urinary infections. Firstly, the
obstructing urine may inhibit complete emptying of the bladder such that a post void residual
urine is left within the bladder. This urine can become stagnant and undergo secondary
and bacterial infection leading to urinary tract infection with symptoms of cystitis.
The second mechanism by which benign prostatic hyperplasia can predispose to urinary tract
infections is that to overcome the obstructing prostate, a bladder needs to increase its
pressure: the force with which it exerts to pass urine. This increased pressure against
an obstructing prostate can force urine into the prostatic ducts. This urine sitting within
prosthetic ducts can cause a chemical inflammation which again can predispose to bacterial infection
leading to symptoms of a urinary tract infection such as cystitis and indeed prostatitis.