Acne is inflammation of the sebaceous glands in the skin. When the pores of the skin become clogged, the oil the sebaceous gland secretes becomes trapped. The plug causes the follicle to bulge (causing whiteheads), and the top of the plug may darken (causing blackheads).
Review Date: 2/27/2018
Reviewed By: David L. Swanson, MD, Vice Chair of Medical Dermatology, Associate Professor of Dermatology, Mayo Medical School, Scottsdale, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.