From the Guidelines
A Complete Blood Count (CBC) report is a crucial diagnostic tool that assesses various components of blood, including red blood cell count, hemoglobin, hematocrit, white blood cell count with differential, and platelet count, to evaluate overall health and detect disorders. The interpretation of a CBC report requires consideration of normal ranges, which vary by laboratory, age, sex, and other factors.
Key Components of a CBC Report
- Red blood cell parameters, such as hemoglobin and hematocrit, assess oxygen-carrying capacity, with low values potentially indicating anemia and high values suggesting polycythemia or dehydration 1.
- White blood cell counts evaluate immune function, with elevated levels often signaling infection, inflammation, or leukemia, while decreased counts may indicate bone marrow problems or certain medications.
- The white blood cell differential breaks down specific types of white cells, helping identify bacterial versus viral infections or allergic reactions.
- Platelet counts reflect clotting ability, with low counts increasing bleeding risk and high counts potentially indicating inflammation or bone marrow disorders.
- Additional measurements like mean corpuscular volume (MCV) and red cell distribution width (RDW) help classify types of anemia, with MCV values indicating microcytic, normocytic, or macrocytic anemia 1.
Interpreting CBC Results
When interpreting CBC results, it is essential to consider clinical symptoms, medical history, and other diagnostic tests, as values slightly outside normal ranges do not always indicate disease. Abnormalities in two or more cell lines should be evaluated carefully and likely warrant discussion with a hematologist 1. A comprehensive approach to evaluating anemia, including morphologic and kinetic approaches, can help identify underlying causes, such as iron deficiency, vitamin B12 or folate deficiency, or bone marrow dysfunction 1.
From the Research
Complete Blood Count (CBC) Report
A CBC report indicates the total numbers and characteristics of cell components in the blood, including:
- Red blood cell count
- Hemoglobin
- Hematocrit
- Red blood cell indices (mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, and red cell distribution width)
- Reticulocyte count
- White blood cell count and differential
- Platelet count 2
Interpretation of CBC Report
The interpretation of a CBC report can lead to a specific diagnosis or assist in ruling out many diseases, when used in conjunction with a good history and physical examination, as well as with additional components of the minimum database, which include a chemistry panel and urinalysis 3. The report can also be used to predict the risk of certain diseases, such as:
- Cancer
- Cardiovascular disease (CVD)
- Arteriosclerosis
- Type 2 diabetes (T2DM)
- Metabolic syndrome 4 Some of the useful markers to predict CVD and metabolic diseases include:
- White blood cell (WBC)
- Neutrophil-to-lymphocyte ratio (NLR)
- Hemoglobin (Hb)
- Mean corpuscular volume (MCV)
- Red cell distribution width (RDW)
- Platelet count
- Mean platelet volume (MPV)
- Platelet-to-lymphocyte ratio (PLR) 4
Diagnostic Uses of CBC
The CBC can be used to diagnose and monitor various medical conditions, including: