Generally speaking, low eosinophil value may be caused by physiological factors or pathologic factors, simple eosinophil hypoplasia has no clinical significance, and needs to be combined with symptoms and other indicators to make a judgment. Eosinophils are a kind of white blood cells, accounting for about 0.5%~5% of the total white blood cells. 1. Physiological: Usually the number of eosinophils has obvious fluctuation of diurnal cycle, usually the number of cells decreases in the early morning, and the number of cells increases in the night. 2. Pathological: If the patient is in burns, after surgery, eosinophils will also be reduced, belonging to the stress reaction, in addition, when suffering from acute leukemia, aplastic anemia, there will also be low eosinophil indicators. It is recommended that patients go to the hospital in time to find out the cause under the guidance of physicians.