A high white blood cell count does not cause disease, but rather indicates the presence of certain diseases. There are five types of white blood cells: neutrophils, lymphocytes, monocytes, eosinophils and basophils. The most important components of white blood cells are neutrophils and lymphocytes, which can be elevated in the presence of infection. If a viral infection is predominant, the lymphocyte count can be elevated; if a bacterial infection is present, neutrophil elevation is predominant. A more pronounced elevation of either cell can lead to an elevated total white blood cell count, and the cause is an infection with a pathogenic microorganism. Also in the case of leukemia and myeloproliferative disorders, it can lead to a significant increase in certain components of the white blood cells, which may be one component or multiple components.