A rare condition involving four heart problems present at birth.

Tetralogy of Fallot is four heart problems present at birth. It is a congenital heart defect. There is a hole in the heart and changes with a heart valve and the body's main artery. The lower right heart chamber wall is thickened. The problems cause low blood oxygen levels. Having measles during pregnancy or a family history of the condition may increase the risk.

Symptoms include shortness of breath and rapid breathing. The skin, lips, and nails may be blue or gray, depending on skin color. Babies with tetralogy of Fallot may cry longer than usual. They may be irritable and unusually sleepy, and they may have poor weight gain.

Surgery is needed to fix the heart. More than one surgery may be needed. Medicines may be given to improve blood flow. Some people may have activity restrictions. Regular health checkups are needed for life.