What is the purpose of white blood cell count and differential?
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 cell count detects dangerously low numbers of white cells. Recovery from illness can be monitored by the white cell count. Counts continuing to rise or fall to abnormal levels indicate a worsening condition; counts returning to normal indicate improvement. Source: The Gale Group. Gale Encyclopedia of Medicine, 3rd ed.
