What is white blood cell count and differential?
Definition The white blood cell count and differential determine the number of white blood cells and the percentage of each type of white blood cell in a person’s blood. These tests are included in general health examinations and help investigate a variety of illnesses, including infection, allergy, and leukemia. Purpose The white blood cell count provides a clue to the presence of illness. White cells protect the body by fighting infection and attacking foreign material. When extra white cells are needed, the bone marrow increases production. There are five types of white cells, each with different functions: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The differential reveals if these cells are present in a normal distribution, or if one cell type is increased or decreased. This information helps diagnose specific types of illness. Conditions or medications that weaken the immune system, such as AIDS or chemotherapy, cause a decrease in white cells. The white cel
