Nuclear left shift and nuclear right shift are abnormalities in the nuclear appearance of neutrophils in pathologic situations, which can reflect their maturity and the occurrence of some diseases. 1. Nuclear left shift: it is defined as the percentage of non-follicular nucleated neutrophils greater than 5% in the peripheral blood. It is common in acute purulent infections, such as acute purulent cholangitis, purulent appendicitis, etc.; it can also be seen in acute blood loss, acute poisoning, etc.; extreme left shift of the nucleus can be seen in leukemia and other conditions. 2. Right shift of nucleus: it is defined as the appearance of five or more lobes of neutrophil nucleus in peripheral blood, and its number is more than 3% of the total neutrophils, which is the manifestation of neutrophil maturation disorder. A rightward shift of the nucleus is often seen in megaloblastic anemia and reduced hematopoiesis of the bone marrow. In conclusion, the presence of nuclear left shift and nuclear right shift, should be timely to the hospital, under the guidance of the doctor for appropriate treatment.