Cyanotic heart disease is a group of birth defects affecting the heart, meaning that the infant’s heart does not develop correctly during pregnancy. The result of this defect is low oxygen levels in the blood, which makes the skin appear blue (cyanotic). Heart defects causing cyanotic heart disease can be caused by drug, chemical or infectious exposure during pregnancy. It is sometimes related to the genetic and chromosomal disorders such as Down syndrome, Marfan syndrome, Turner syndrome, and Noonan syndrome. The main symptom of cyanotic heart disease is bluish lips, fingers and toes, particularly when the infant is feeding or crying. Some may also experience trouble breathing. Spells of low oxygen are common and may cause anxiety, breathing too quickly or sudden increase in blue color. Cyanotic heart disease can be diagnosed in a physical examination by a physician, but this may require further tests and imaging, such as an x-ray of the heart or an echocardiogram. Most infants diagnosed with cyanotic heart disease at birth will have to stay in the hospital to receive oxygen and further medical care. The suggested treatment for cyanotic heart disease is surgery to repair the defect. This surgery may occur shortly after birth, or in some cases it can be delayed a number of months or years.