The prostate is a small gland that is part of the male reproductive system. Throughout a man's life, the prostate produces semen, the fluid that contains sperm. As men age, the prostate gland may grow in size. This condition is referred to as an enlarged prostate or benign prostatic hyperplasia (BPH). Due to the position of the prostate in front of the bladder, BPH can cause pressure on the urinary system, and may cause a number of unpleasant symptoms.