Benign prostatic hyperplasia refers to the increase in size of the prostate in middle-aged and elderly men. To be accurate, the process is one of hyperplasia rather than hypertrophy, but the nomenclature is often interchangeable, even amongst urologists. It is characterized by hyperplasia of prostatic stromal and epithelial cells, resulting in the formation of large, fairly discrete nodules in the periurethral region of the prostate. When sufficiently large, the nodules compress the urethral canal to cause partial, or sometimes virtually complete, obstruction of the urethra which interferes the normal flow of urine. It leads to symptoms of urinary hesitancy, frequent urination, increased risk of urinary tract infections and urinary retention. Although prostate specific antigen levels may be elevated in these patients, because of increased organ volume and inflammation due to urinary tract infections, BPH is not considered to be a premalignant lesion.