Abbreviated BPH. A noncancerous prostate problem in which the normal elements of the prostate gland grow in size and number. Their sheer bulk may compress the urethra, which courses through the centre of the prostate, impeding the flow of urine from the bladder through the urethra to the outside. This leads to urine retention and the need for frequent urination. If BPH is severe, complete blockage can occur.