Examination of Blood Count

Importance of Blood Count Examination

Examination of the blood counts and their appearance on a blood film is central to the diagnosis of blood cell diseases and can give important information about numerous other degenerative, inflammatory, and neoplastic diseases that are reflected in quantitative or qualitative changes of blood cells.

Examples of Blood Count Usage

Examples are the anemia accompanying chronic renal disease, chronic inflammation, or iron deficiency, the presence of malarial parasites in red cells, the eosinophilia of parasitic infection, the decrease in platelets resulting from immune thrombocytopenia, and other key findings on a blood examination that reflect numerous disease states.

By careful examination of the blood, an experienced observer can diagnose all types of leukemia and closely related diseases. In few other disciplines can a physician make a specific diagnosis with easily accessible tissue samples and methods that can be used in a physician’s office.

Today, blood count examination is conducted almost exclusively in diagnostic laboratories, but the results can be provided to the clinician within a few hours of drawing the sample.

Complete Blood Count

Assessment of the concentration of red cells, reticulocytes, leukocytes, specific leukocyte types, and platelets; morphology of red cells, white cells, and platelets; identification of intracellular parasites, malignant cells, and marrow precursors (e.g., nucleated red cells) provides a large amount of information from the “complete blood count,” quickly and accurately.

The complete blood count is a necessary part of the diagnostic evaluation in a broad variety of clinical conditions. Similarly, the leukocyte differential count and examination of the blood film, in spite of limitations as a screening test for occult disease, is important in initial consideration of the differential diagnosis in most ill patients. The distinction between quantitative and morphologic examination of the cells of the blood is not absolute, and measures once considered “qualitative” become quantitative as technology advances.