The exact mechanism for development of an enlarged prostate/ BPH remains unclear, however, there are certain factors that are obviously involved. Firstly, it is clear that a normal level of male hormone, which is produced mainly from the testes, is essential to the development of BPH. We know that individuals that have impaired production do not develop increased prostatic growth later in life. Also, it is clear from treatments that impair the production (commonly used in advanced prostate cancer) that there can be a significant reduction in prostate size with these agents. The active form or metabolite of the hormone is called DHT. There are medications available that prevent the formation of this metabolite and can be used to reduce the size of the prostate by approximately 20 to 30%. From these facts it is clear that it is integral to the development of BPH.