Acne is an inflammation of the skin that causes blackheads, whiteheads, and red spots usually called "pimples" or "zits." The most common type of acne is acne vulgaris (vulgaris means common). Acne appears most often on the face, but can also be a nuisance on your chest, back, and upper arms. Acne affects about 90% of adolescents and can also occur in adulthood, usually affecting people aged 20 to 40 years. It accounts for more doctor visits than any other skin problem.
Acne isn't life-threatening, but it can be upsetting and disfiguring and cause psychosocial problems. Acne can also lead to serious and permanent scarring.