A normal white blood count ranges from 4,500 to 10,000 cells per microliter, states MedlinePlus. Since results may differ based on the laboratory used, patients are advised to discuss individual results with their physician.
A low white blood cell count may be caused by certain viral illnesses, bone marrow problems, cancer treatment, autoimmune disorders or conditions involving the liver or spleen, according to the National Library of Medicine. Elevated white blood cells counts may occur because of cigarette smoking, stress, tissue damage, inflammatory diseases and bacterial infections.
Medications such as corticosteroids, albuterol, heparin and lithium may be used to raise the number of white blood cells.