Emotional colds need to be examined A clinical diagnosis can be made based on history, epidemiology, signs and symptoms of nasopharyngeal inflammation, combined with peripheral blood picture and chest X-ray. Bacterial culture and viral isolation, or viral serology, immunofluorescence, enzyme-linked immunosorbent assay, and hemagglutination inhibition test are performed to determine the etiologic diagnosis. If none of the above is evident, an emotional cold is likely. White blood cells are low, with a slight increase in neutrophils in the early stages. Combined with bacterial infection total leukocytes and neutrophils may be increased. Blood Picture Viral infections are seen with normal or low white blood cell counts and an elevated lymphocyte ratio. Bacterial infections are characterized by a leukocyte count with neutrophilia and a left shift of the nucleus. Determination of viruses and viral antigens Immunofluorescence, enzyme-linked immunosorbent assay (ELISA), serological diagnostic methods, and viral isolation and characterization may be used as needed to determine the type of virus and to differentiate between viral and bacterial infections. Bacterial cultures are used to determine bacterial type and drug sensitivity tests.