Water vapor therapy is a minimally invasive office-based treatment for benign prostatic hyperplasia (BPH). It uses controlled doses of steam (water vapor) delivered through a small device inserted into the urethra. The steam causes targeted prostate tissue cells to die, and over the following weeks the body absorbs the treated tissue, reducing the size of the prostate and relieving obstruction. This therapy can improve urinary flow and reduce symptoms like frequency, urgency, and weak stream, often without the need for long-term medications. Side effects are usually temporary and may include burning with urination, urgency, or blood in the urine, but serious complications are uncommon.