RDW
A measure of how variable your red blood cell sizes are.
What is it
RDW measures the variation in red blood cell size. Elevation has been associated with various conditions in research literature, beyond just anemia.
Why it's measured
RDW has been studied as a marker not just of anemia but of inflammation, mortality risk, and certain chronic conditions in published research.
Reference range
Standard laboratory reference
11.5 – 14.5 %
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with various anemias, inflammation, and elevated mortality risk in published research.
Lower
Generally considered favorable.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Part of standard CBC.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.