Hair loss on the top of the head is commonly known as androgenetic baldness. Hair follicles in different parts of the scalp have different sensitivities to androgens, with the top of the head often being the earliest area to develop, while hair follicles in surrounding areas do not experience hair loss because they have not yet shown sensitivity to androgens.
More common is baldness and, less commonly, scarring alopecia such as flatulent hair moss, where hair is shed from follicles damaged by inflammatory cell infiltration, whereas hair follicles in the surrounding scalp without inflammatory cell infiltration do not lose hair.