Red Cell Distribution Width (RDW)

Email

Send Email

Recipient(s) will receive an email with a link to 'Red Cell Distribution Width (RDW)' and will have access to the topic for 7 days.

Subject: Red Cell Distribution Width (RDW)

(Optional message may have a maximum of 1000 characters.)

×


Definition

  • RDW is a coefficient of variation of the distribution of individual RBC volume.

  • Normal range: 12.1–14 fL.

Use

  • An elevation in RDW is useful in drawing attention to anisocytosis, a marker for various anemias.

Interpretation

  • The RDW is particularly helpful in separating iron deficiency anemia (high RDW, normal to low MCV) from β-thalassemia trait (normal RDW, low MCV).

  • Increased RDW is also useful in identifying red cell fragmentation, agglutination, or dimorphic cell populations.

Limitations

  • Very high WBC, numerous large platelets, and autoagglutination result in falsely elevated RDW.

 
×