The prostate gland is the male organ that produces most of the fluid in semen, the milky-colored fluid that nourishes and transports sperm out of the penis during ejaculation (orgasm). It sits beneath your bladder. The tube that transports urine from the bladder out of your penis (urethra) passes through the center of the prostate. So, when the prostate enlarges, it begins to block (obstruct) urine flow.

Most men have continued prostate growth throughout life. In many men, this continued growth enlarges the prostate enough to cause urinary symptoms or to significantly block urine flow. Doctors aren't sure exactly what causes the prostate to enlarge. It may be due to changes in the balance of sex hormones as men grow older.

Dec. 06, 2011

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