The exact cause of benign prostatic hyperplasia (BPH) is not fully understood. Prostate enlargement becomes more common with increasing age and is thought to be influenced by changes in male hormones, including dihydrotestosterone (DHT).
BPH is very common in older men, although the degree of prostate enlargement does not always correspond with the severity of urinary symptoms. Some men with a significantly enlarged prostate have few symptoms, while others with a smaller prostate may experience troublesome urinary symptoms.