Androgenetic : Commonly called baldness. Has a genetic predisposition and can manifest in men abd women.
Alopecia areata: Is hereditary, especially in people with autoimmune problems.
Diffusa: The hair density decrease over whole scalp surface.
Scarring: Is caused by loss of follicular ostia and creation of scars, caused by various inflammatory skin conditions (e.g. cellulitis, bursitis, acne) and other skin diseases.