Acne is a recurring, inflammatory skin condition characterized by pimples mainly on the face, but can also affect the chest, back, neck, and shoulders. There is no single cause of acne, but it is believed to be triggered by a rise in the level of the hormone androgen. This hormone increases when adolescence sets in, which is why acne is more common during the period of puberty. The oil glands under the skin get enlarged when androgen levels rise, producing more sebum. Too much sebum can break down the pores’ cellular walls, resulting in the growth of bacteria. These bacteria then lead to acne. Acne can be classified into six main types: blackheads, whiteheads, pustules, papules, cysts, and nodules.