The prostate is a gland located in front of the rectum and underneath the urinary bladder. It is found only in men. The size of the prostate varies with age. In younger men, it is the size of a walnut, but it can be much larger in older men. The prostate's job is to make some of the fluid that protects and nourishes sperm cells in semen, making semen more liquid. Just behind the prostate gland are the seminal vesicles that make most of the fluid for semen. The urethra, which is the tube that carries urine and semen out of the body through the penis, goes through the center of the prostate.

The prostate starts to develop before birth and continues to grow until a man reaches adulthood. This growth is fueled by male hormones (called androgens) in the body. The main androgen, testosterone, is made in the testicles. The enzyme 5 alpha-reductase converts testosterone into dihydrotestosterone (DHT). DHT signals the prostate to grow. The prostate stays at adult size in adults as long as male hormones are present. In older men, the inner part of the prostate (around the urethra) often keeps growing, leading to a common condition called benign prostatic hyperplasia (BPH). In BPH, the prostate tissue can press on the urethra, leading to problems passing urine. BPH can be a serious medical problem, but it is not cancer.

Posted in: Prostate Cancer