Anemia is detected by measuring RBCs, hemoglobin, and hematocrit. These parameters are then compared to established reference intervals considering age, gender, and race. Borderline anemic individuals may not be diagnosed by evaluating these three parameters alone. For an appropriate diagnosis, blood smear evaluation, reticulocyte count, RBC indices, and RBC distribution width should be included.
There are three primary methods for classifying anemias. These are:
- Classification of anemias based on mean cell volume (MCV) and red cell distribution width (RDW)
- Morphologic classification
- Pathophysiologic classification
The following table categorizes anemias according to MCV and RDW.
Table 3. Anemias Categorized by MCV and RDW.MCV
| RDW (Heterogeneity)
| Classification
|
Low
| Normal
| Microcytic homogenous
|
Low
| High
| Microcytic heterogenous
|
Normal
| Normal
| Normocytic homogenous
|
Normal
| High
| Normocytic heterogenous
|
High
| Normal
| Macrocytic homogenous
|
High
| High
| Macrocytic heterogenous
|
