Acne, or acne vulgaris, is a skin problem that starts when oil and dead skin cells clog up your pores. Some people call it blackheads, blemishes, whiteheads, pimples, or zits. When you have just a few red spots, or pimples, you have a mild form of acne. Severe acne can mean hundreds of pimples that can cover the face, neck, chest, and back. Or it can be bigger, solid, red lumps that are painful (cysts).
Acne is very common among teens. It usually gets better after the teen years. Some women who never had acne growing up will have it as an adult, often right before their menstrual periods.