Prostate Enlargement
The prostate is normally about the size and shape of a walnut and weighs about 20 grams (less than 1 ounce). As men age, the prostate gradually increases in size. Generally, the prostate does not grow beyond about twice its normal size because the outer capsule of the gland restricts expansion. Because of this restriction, further tissue growth compresses against the inside of the gland, which can constrict the urethra and cause urinary symptoms.
Prostate enlargement appears to be a normal process because it is so common. The only factor that can prevent prostate enlargement from eventually occurring is the elimination of testosterone. Men who have had their testicles removed or have had diseases that left them unable to produce testosterone do not develop BPH or prostate cancer.
Prevalence of BPH
More than one-half of men over the age of 70 have symptomatic BPH, and nearly 90% of men have microscopic evidence of an enlarged prostate. Moderate-to-severe symptoms also become more common with increasing age: 17% of patients in their 50s suffer from moderate-to-severe symptoms, while 27% experience such symptoms in their 60s and 37% in their 70s.
