What causes erectile dysfunction?
Erectile dysfunction is most often vascular and metabolic — endothelial dysfunction, atherosclerosis, hypertension, diabetes — with hormonal, neurological, medication-related, and psychological contributors. ED is frequently the first symptom of underlying cardiovascular disease.
Full answer
Erectile dysfunction is rarely a single-mechanism problem. The dominant drivers in men over 40 are vascular: endothelial dysfunction, atherosclerosis, hypertension, and insulin resistance / diabetes — all of which impair the nitric-oxide-mediated vasodilation an erection requires. Because the penile arteries are smaller than the coronary arteries, ED frequently appears years before a cardiovascular event and is increasingly treated as an early cardiovascular signal. Secondary contributors include low testosterone, thyroid dysfunction, prolactin elevation, certain medications (some antihypertensives, SSRIs, opioids), pelvic-floor dysfunction, sleep apnea, alcohol, smoking, and psychological factors. Provider review assesses the full panel — cardiometabolic, hormonal, and contextual — before recommending PDE5 therapy, hormone optimization, or both.
Educational. Not a substitute for individualized provider review.
- Erectile Dysfunction — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-05-29