Below is an overview of commonly hair and scalp conditions:

Alopecia areata
Androgenetic alopecia
Telogen effluvium
Anagen effluvium
Traction alopecia
Trichotillomania
Premature greying
Hypertrichosis
Hirsutism
Dandruff
Seborrheic dermatitis
Psoriasis of the scalp
Seborrheic dermatitis
Eczema
Folliculitis
Furunculosis
Lichen planopilaris
Discoid lupus erythematosus
Scalp cellulitis
Pediculosis capitis
Tinea capitis
Scalp cysts
Kerion