When children are severely anemic, the red blood cells and hemoglobin in the blood will be reduced, because the main role of hemoglobin is to carry oxygen and supply it to the organs of the whole body for application, so the above situation will result in the insufficient supply of blood and oxygen to various systems. If the cardiomyocytes have insufficient blood and oxygen supply, the heart will be compensated to increase in size, and over time, pathological heart enlargement and cardiac hypertrophy will occur, followed by cardiac insufficiency, and heart murmurs such as incomplete heart closure and blood reflux will be heard in the area of mitral, tricuspid, or aortic valves when auscultation is performed. There are many types of anemia in children, including iron deficiency anemia, megaloblastic anemia, thalassemia, etc. Regardless of the type of anemia, it should be corrected in a timely manner and treated aggressively under the guidance of a physician to avoid other complications.