Tetralogy of Fallot is a congenital heart defect that consists of four specific heart abnormalities. These include a ventricular septal defect (a hole between the heart's lower chambers), pulmonary stenosis (narrowing of the outflow tract from the heart), right ventricular hypertrophy (thickening of the heart muscle), and an overriding aorta (the aorta is positioned directly over the ventricular septal defect). This condition affects blood flow and oxygen delivery to the body, leading to symptoms like cyanosis (bluish skin) and difficulty breathing. Treatment typically involves surgery to correct the defects, allowing for improved heart function and quality of life for those affected.