Benign prostatic hyperplasia (BPH) is the most common condition to affect older men. Almost half of all men older than 65 years have lower urinary tract symptoms (LUTS), consisting of poor flow and frequency of micturition, which may have a severely negative impact on quality of life. As BPH is generally a disorder of older men, it is frequently associated with comorbid conditions such as erectile dysfunction, hypertension and prostate cancer. These need to be identified and taken into account at the time of diagnosis, as their presence may impact on treatment strategies.The main risk factors for BPH are age, family history and possibly obesity.[With external links to the evidence base]