The benign prostatic hyperplasia is characterized by an expansion in size of the prostate due to increased cell growth (hyperplasia). Most growing cells are located in the transitional zone of the prostate, found in the inner part of the prostate. As we age, especially after age 50, the prostate naturally becomes larger following testosterone. Almost all men have a prostate larger at the age of 70. BPH does not increase the risk of developing prostate cancer.