Lack of oxygen in the blood causes a bluish discoloration in the skin or mucous membranes called cyanosis. Most cyanosis is seen as a result of congenital heart disease, pulmonary disease, or as a terminal event as in cardiopulmonary arrest.
Update Date 4/21/2013
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.