When a fever is accompanied by an elevated white blood cell, most often the fever is caused by a bacterial infection. However, if C-reactive protein is also elevated, the diagnosis of elevated white blood cells and fever due to infection can be confirmed. In this case, the toxins secreted by the bacteria often stimulate the thermoregulatory center in the body, causing an increase in the thermoregulatory point, so that the fever is caused, and antibiotics are needed for treatment. If the fever is not very serious and the elevated white blood cell value is not very obvious, you can take oral antibiotics for treatment, such as cefradine, cefixime and cefadroxil. If the leukocyte count is high and the fever is severe, intravenous antibiotics such as levofloxacin and ceftriaxone are required. If there is no elevation of C-reactive protein, but only fever and elevated white blood cells, it is likely that a hematologic disorder is occurring and a bone marrow aspiration is required to confirm the diagnosis.