The Hamilton Norwood scale is used for:
Ludwig scale is used in female pattern hair loss. The most common pattern of hair loss seen in women is diffuse reduction of hair density over the crown, so-called Christmas-tree pattern, with widening of the central paing line. Ref: Rook's textbook of dermatology, Edition-8, Page-66.18.
Male androgenetic alopecia
Female androgenetic alopecia
Alopecia areata
Telogen effluvium