The causes of EOS% Eosinophils 7.90% may include suffering from allergic diseases, parasitic infections, hematologic disorders, skin diseases, endocrine and metabolic disorders, and malignancies. Eosinophils are a type of normal human leukocyte that has the function of killing bacteria and parasites, as well as regulating immunity and anti-allergy. The percentage of eosinophils is 7.90%, suggesting that eosinophilia may have the following causes: 1. allergic diseases: such as drug allergy, food allergy, bronchial asthma, urticaria, etc. 2. Parasitic infections: e.g. schistosomiasis, ascariasis, tapeworm infection, etc. 3. Hematologic disorders: e.g. eosinophilia, eosinophil granuloma, etc., which can lead to an increase in the percentage of eosinophils. 4. Skin diseases: such as eczema, exfoliative dermatitis, psoriasis, etc. 5. Certain endocrine and metabolic diseases, such as hypopituitarism, hypoadrenocorticism, etc. 6. Malignant tumors, such as chronic granulocytic leukemia and multiple myeloma. When the percentage of eosinophils is 7.90%, it is recommended to find a specialist for diagnosis and treatment according to one’s own condition, and not to take it lightly in order to avoid delaying the condition.