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Red Cell Distribution Width

RDW RDW-CV
EDTA whole blood %

About this test

Measure of variation in red cell size (anisocytosis). High RDW indicates mixed or evolving anaemia.

Reference Ranges

Sex Age Range Notes
All ≥ 18 yrs 11.5 – 14.5 Adult

Clinical Interpretation

Low / Decreased
Normal RDW with low MCV suggests thalassaemia trait.
High / Increased
Elevated — iron deficiency (early), B12/folate deficiency, mixed deficiency anaemia, haemolysis.

Related Tests

Vitamin B12 Ferritin
Specimen
EDTA whole blood
Reporting Unit
%
Category
🩸 Hematology

⚠ Clinical Note
Reference ranges are indicative. Always interpret results in the context of the individual patient and local laboratory reference intervals, which may vary.