What is the red cell distribution width (RDW) typically seen in thalassemia?

In thalassemia, the red cell distribution width (RDW) is typically normal. RDW is a measurement that reflects the variation in the size of red blood cells (erythrocytes). In conditions where there is significant variation in cell size, such as iron deficiency anemia, the RDW tends to be increased due to the presence of both small (microcytic) and larger cells.

In thalassemia, however, the red blood cells are often uniformly microcytic, leading to a normal RDW because the size variation is minimal. This characteristic helps differentiate thalassemia from other microcytic anemias. Thus, the normal RDW in thalassemia is a useful clinical point in the evaluation of patients presenting with microcytic anemia, assisting clinicians in determining the underlying cause.