Benign enlargement of the prostate gland does not always cause symptoms or obstruction to the flow of urine. Old terminology, for example, ‘prostatism’ can therefore be misleading, and the British Association of Urological Surgeons (BAUS), the International consultation on BPH and the International Continence Society accept the definitions given below:

Benign prostatic hyperplasia (BPH) is a histological diagnosis. The first pathological signs appear under the age of 40 years, followed by a rapid increase in prevalence with age; 80% of 80-year-olds have evidence of BPH. The onset of BPH is dependent on the presence of functioning testes and increasing age. It is characterized by a combination of atrophy and proliferation in both glandular and stromal tissue. Although BPH is detectable in most elderly men, it does not always cause enlargement of the prostate, symptoms, or obstruction to the flow of urine.