Low eosinophil ratio is mostly physiologic and usually has no symptoms; a few can be seen in long-term application of adrenocorticotropic hormone, acne, hirsutism, centripetal obesity (full moon face, buffalo back) and other symptoms. 1. Low eosinophil ratio may be physiological, because eosinophils have obvious diurnal fluctuations (decrease in the morning, increase in the midnight), if the examination in the early morning can appear eosinophil ratio is low, the body will not have any symptoms. 2. Eosinophils are also affected by fluctuations in the body’s corticosteroid, when the blood concentration of corticosteroid is high eosinophilic reduction can be seen in the long-term application of adrenocorticotropic hormone (Prednisone) people, this group of people usually have long-term application of corticosteroid adverse reactions, such as acne, hirsutism, centripetal obesity (full moon face, buffalo back) and other symptoms. Specific diagnosis and treatment should be directed by a physician.