Indicators to determine whether anemia exists in infants, the degree of anemia and the cause of anemia, we mainly include the following categories.1. Red blood cell count and hemoglobin level: clinically, low hemoglobin level is more common, if the value of infant hemoglobin is less than 145g/L, 1-3 months old child hemoglobin is less than 90g/L, 3-6 months old child hemoglobin is less than 100g/L. Children aged 6 months-1 year with hemoglobin less than 110g/L can be considered anemic. Therefore, the criteria for anemia vary for infants of different ages. 2. MCV, MCH and MCHC: The three indicators are mean red blood cell volume (MCV), mean red blood cell hemoglobin volume (MCH) and mean red blood cell hemoglobin concentration (MCHC). If both MCV and MCH are significantly larger than normal, the child has macrocytic anemia, such as megaloblastic anemia caused by folic acid or vitamin B12 deficiency. If all three values are less than normal, the child has microcytic hypochromic anemia, such as iron deficiency anemia or thalassemia. 3. reticulocytes: its normal value is usually between 0.5% and 1.5%, if reticulocytes are significantly higher, it often indicates hemolytic anemia. It should be noted that during the growth and development of infants, some of them may have mild anemia, which usually disappears on its own with developmental perfection, so parents need not worry too much. To determine whether an infant is anemic or not, apart from the indicators, it is also necessary to take into account whether there are clinical manifestations such as white or yellow lips, mucous membranes, face and nail bed, or the infant’s body is developing too slowly, so that the cause can be found through examination and active treatment.