Introduction of the test

Red blood cell volume distribution width (RDW-SD) is a parameter reflecting the heterogeneity of red blood cell volume size, and is often referred to as the coefficient of variation of the measured red blood cell volume size. It is a parameter that reflects the heterogeneity of peripheral blood erythrocyte volume as measured by a hematology analyzer. In short, it is an objective indicator of inequality in red blood cell size. Morphological classification of anemia is generally performed by two parameters, RDW and MCV.

The clinical significance can be mainly combined with the MCV (mean corpuscular volume of red blood cells) for the morphological classification of anemia, which can be classified as:

1. Anemia, small-cell homogeneity (MCV ↓ RDW normal)

2. Anemia, small-cell inhomogeneity (MCV ↓ RDW ↑)

3. Anemia, orthoclonal homogeneity (MCV normal, RDW normal)

3. RDW normal)

4. Anemia, orthoclonal heterogeneity (MCV normal RDW↑)

5. Anemia, macrocytic homogeneity (MCV↑RDW normal)

6.