The prostate is part of a man's reproductive system. It is located in front of the rectum and under the bladder. A healthy prostate is about the size of a walnut, and it is shaped like a donut. The urethra (the tube through which urine flows) passes through the prostate. If the prostate grows too large, it squeezes the urethra. This may cause urinary problems by slowing or stopping the flow of urine from the bladder to the penis.
The prostate is a gland that makes part of seminal fluid. During ejaculation, seminal fluid helps carry sperm out of the man's body as part of semen.
Male hormones (androgens) make the prostate grow. The testicles are the main source of male hormones, including testosterone. The adrenal glands also make testosterone, but in small amounts.
