From the Guidelines
A Complete Blood Count (CBC) typically includes tests for red blood cells (RBCs), white blood cells (WBCs), and platelets, and is used to assess overall health and detect various conditions such as anemia, infection, inflammation, bleeding disorders, and certain cancers. The tests ordered in a CBC include:
- Red blood cell count
- White blood cell count with differential (neutrophils, lymphocytes, monocytes, eosinophils, and basophils)
- Platelet count
- Hemoglobin, which carries oxygen in the blood
- Hematocrit, the percentage of blood volume occupied by RBCs
- Red blood cell indices including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) 1. These measurements help assess bone marrow function, and abnormalities in two or more of these cell lines should be evaluated carefully and likely warrant discussion with a hematologist. The CBC is one of the most commonly ordered blood tests because it provides a broad overview of blood cell production and function, and results outside normal ranges may indicate the need for further testing to determine specific diagnoses, as recommended by various guidelines, including those for the management of persons infected with HIV 1 and the use of antimicrobial agents in neutropenic patients with cancer 1. No special preparation is typically required before having a CBC test performed.
From the Research
Components of a CBC
The following are the tests typically ordered in a Complete Blood Count (CBC):
- Red blood cell count
- Hemoglobin
- Hematocrit
- Red blood cell indices, including:
- Reticulocyte count
- White blood cell count and differential
- Platelet count
- Mean platelet volume (MPV) 2
Additional Markers
Other useful markers that can be predicted using CBC components include: