While it sounds like something out of a cartoon, bluish skin, or cyanosis is a very real medical condition. When this happens it is usually the result of low blood oxygen levels and is almost always indicative of a more serious, underlying issue.
According to Dr. Ananya Mandal, MD, “Cyanosis is seen in the skin, nail beds, or mucous membranes. If cyanosis is seen only in the limbs it is termed acrocyanosis or peripheral cyanosis. This is common in young infants and is a part of normal physiology. However, central cyanosis affects the whole body. This is seen in the mucous membranes and tongue. This usually means a potentially serious and life-threatening disease is lying underneath and requires immediate evaluation. Major systems that may be affected include the respiratory system, blood, heart or cardiovascular system and the central nervous system.”