The prostate is a gland that only men have, at the base of the bladder. Most men over 50 years have some enlargement of the prostate gland, benign prostatic hypertrophy (called benign because it is not caused by cancer). It causes difficulty passing urine when the prostate starts to obstruct the outflow of urine from the bladder. This can lead to never being able to fully empty the bladder (chronic retention of urine) or to being completely unable to pass any urine (acute retention of urine). Without treatment these problems can ultimately lead to kidney failure.
Benign prostatic hypertrophy caused 0.06% of all deaths worldwide in 2002, an average of 5 deaths per million people per year.