Final answer:
Whiteheads and blackheads are referred to as comedones, non-inflammatory acne lesions caused by clogged hair follicles. Whiteheads remain covered by skin, whereas blackheads get their color from the oxidation of exposed sebum.
Step-by-step explanation:
Whiteheads or blackheads can also be referred to as comedones. These are non-inflammatory skin lesions that occur when hair follicles are clogged by dead skin cells and sebum, leading to acne. A whitehead is covered by skin and stays white because it is not exposed to air, while a blackhead appears dark because the lipids in the sebum oxidize when exposed to air. Comedones result from the blockage of hair follicles due to the overproduction of sebum, often influenced by hormonal changes such as those experienced during puberty. If comedones become infected by acne-causing bacteria, they can evolve into more severe inflammatory lesions, such as papules, pustules, nodules, or cysts.