What causes hair loss in men?
Male hair loss is most often androgenetic (genetic + DHT). Other causes include iron deficiency, thyroid dysfunction, severe stress, and certain medications. Workup screens reversible causes.
Full answer
Male pattern hair loss (androgenetic alopecia) accounts for most adult male hair loss and reflects a genetic predisposition to follicle sensitivity to dihydrotestosterone (DHT). Other causes include iron deficiency, low ferritin, thyroid dysfunction, severe acute stress (telogen effluvium), nutritional deficiencies, and certain medications. The provider-reviewed workup screens for reversible causes first — ferritin, TSH, Free T4, vitamin D, B12, total and free testosterone, DHT — before committing to long-term hair-loss therapy.
Educational. Not a substitute for individualized provider review.
- DHT — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-05-29