The Norwood-Hamilton scale classifies common male pattern hair loss patterns, especially temple recession, frontal loss and vertex thinning. It is useful for describing severity, tracking progression and planning treatment, including hair transplantation. It does not diagnose the cause by itself; it describes a pattern. Two men with the same Norwood stage may have different donor quality, age of onset, family history and treatment needs. In a clinical context, staging should be combined with trichoscopy, photographs and a long-term plan for future progression.
Anastassakis K. Androgenetic Alopecia From A to Z, Vol. 1, Springer, 2022 — https://doi.org/10.1007/978-3-030-76111-0; British Association of Dermatologists: Hair loss male pattern (androgenetic alopecia) — https://www.bad.org.uk/pils/hair-loss-male-pattern-androgenetic-alopecia
