The Prostate is an organ forming part of the male reproductive system. It is located immediately below the bladder and just in front of the bowel. Its main function is to produce fluid which protects and enriches sperm. In younger men the prostate is about the size of a walnut. It is doughnut shaped as it surrounds the beginning of the urethra, the tube that conveys urine from the bladder to the penis. The nerves that control erections surround the prostate.

Benign prostatic hyperplasia (also called BPH) is a condition that affects the prostate gland in men. The prostate is a gland found between the bladder (where urine is stored) and the urethra (the tube urine passes through). As men age, the prostate gland slowly grows bigger (or enlarges). As the prostate gets bigger, it may press on the urethra and cause the flow of urine to be slower and less forceful. "Benign" means the enlargement isn't caused by cancer or infection. "Hyperplasia" means enlargement.