Only men have a prostate. It is a small gland that sits below the bladder near the rectum. It surrounds the urethra, the passage in the penis through which urine and semen pass.
The prostate gland is part of the male reproductive system. It produces most of the fluid that makes up semen that enriches sperm. The prostate needs the male hormone testosterone to grow and develop. The prostate is often described as being the size of a walnut and it is normal for it to grow as men age. Sometimes this can cause problems, such as difficulty urinating. These problems are common in older men and not always symptoms or signs of cancer