Hemolytic index is the lowest concentration of red blood cells that can be completely dissolved under certain conditions, mainly for diseases or conditions such as blood transfusion, hemolytic anemia, and preterm delivery in pregnant women. The normal value of hemolytic index is about 1.64. Elevated hemolytic index represents the phenomenon of hemolysis, which can be caused by common blood transfusion reaction, hemolytic anemia, hemolytic jaundice in newborns, etc. 1. Transfusion reaction: the hemolytic destruction of red blood cells in the recipient’s body due to mismatch of blood types during blood transfusion will cause more serious consequences, so cross-matching check will be carried out before blood transfusion. 2. Hemolytic anemia: a common type of anemia, often caused by autoimmune destruction of red blood cells in the blood vessels, in addition to fever and jaundice and other manifestations, the need for immune-suppressive treatment, drugs, including methylprednisolone and so on. 3. Incompatibility between the blood type of the baby and the mother: in addition to the ABO blood type, there is also the Rh blood type that leads to hemolysis of the fetus, and when the blood type is incompatible with the blood type, it can easily lead to miscarriage and premature birth, and requires special attention. When there is obvious abnormality in the indicators, it is necessary to actively seek medical advice and reasonable treatment under the guidance of physicians.