Benign prostatic hyperplasia (BPH) is a noncancerous enlargement of the prostate gland caused by changes in hormone levels as men age. It involves the proliferation of cells within the prostate and commonly causes urinary symptoms like frequent urination, weak urine stream, and incomplete emptying of the bladder. Diagnosis involves a digital rectal exam, urinalysis, and tests to evaluate urine flow and residual urine in the bladder. While not cancerous, BPH can lead to complications like urinary tract infections if left untreated.