The actual cause of prostate enlargement is unknown. Factors linked to aging and the testicles themselves may play a role in the growth of the gland. Men who have had their testicles removed at a young age (for example, as a result of testicular cancer) do not develop BPH.
Similarly, if the testicles are removed after a man develops BPH, the prostate begins to shrink in size.
Some facts about prostate enlargement: