The prostate is a small, muscular gland in the male reproductive system. Your prostate surrounds your urethra and produces most of the fluid in your semen. The muscular action of the prostate helps propel the fluid and semen through your penis during sexual climax.

Benign prostatic hypertrophy, or benign prostatic hyperplasia (BPH), occurs when the cells of the prostate gland begin to multiply. These additional cells cause your prostate gland to swell, which squeezes the urethra and limits the flow of urine.