Alfuzosin is used to treat benign prostatic hyperplasia (BPH) in adult men. It helps relax the muscles in your prostate and bladder, which can reduce BPH symptoms and improve your ability to urinate. Benign prostatic hyperplasia, also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, inability to urinate, or loss of bladder control.