This common skin condition is the formation of multiple blemishes on or just beneath the surface of the skin. These blemishes commonly appear on the face, neck, chest, shoulders and back. Acne can affect anyone, but it most commonly affects adolescents and young adults.


Acne occurs when the small openings in the skin, called pores, become blocked with dead skin cells and oil. A blocked pore causes a buildup of oil in the sebaceous glands. These are the oil-producing glands of the skin. When trapped oil builds up within these glands, bacteria can multiply rapidly. This causes inflammation of the surrounding tissues.

Types of Blemishes

Acne blemishes may take the form of large pustules (called pimples) or small red bumps (called papules). A person who has acne may develop small, dark clogged pores (called blackheads) or small white bumps (called whiteheads). Small nodules or cysts may form beneath the skin.


Acne breakouts can be triggered by the hormonal changes of puberty or pregnancy. Acne can also be caused by certain medications, and by a diet rich in dairy or carbohydrates. Acne is not caused by eating greasy or sugary foods or by having dirt on the skin.


Acne is typically treated with cleansing products designed to remove excess oil and bacteria from the skin. It can also be treated with prescription-strength topical or oral medications, laser or light therapy, and cosmetic procedures such as chemical peels and microdermabrasion.