why would rdw be elevated
The RDW is elevated in these conditions. â¢ RDW is useful in differentiating thalassaemia from iron deficiency anaemia. In thalassaemia, the RDW is normal while in iron deficiency anaemia the RDW is elevated. However, additional tests may be required to confirm the diagnosis. â¢ In conditions such as vitamin B12 deficiency and folate deficiency, the size of the red blood cells can increase. This is called macrocytosis.