RDW Test | Red Cell Distribution Width Test | RBC Indices | RDW And MCV Comparison |

RDW is a shortfor Red Cell Distribution Width

The test measures the differences in the volume and size of your RBCs


What is it used for?

The RDW blood test is often part of CBC

The RDW test is commonly used to help diagnose anemia,

The test may also be used with other tests to help diagnose other conditions, including thalassemia


Why do I need an RDW test?

It may be ordered as part of routine CBC, if you have:

Symptoms of anemia

A family history of thalassemia, sickle cell anemia, or other inherited blood disorder

A chronic illness such as Crohn's disease, diabetes, or HIV/AIDS

A diet low in iron and other minerals

A long-term infection

Excessive blood loss from an injury or surgical procedure

How its calculated

usually calculated by dividing the standard deviation (SD) of the MCV,... by the MCV and.... multiplying by 100

RDW = 1 SD ÷ MCV × 100

Results

Test results appear as a percentage

Generally, a normal RDW ranges from 12% to 15


A normal result means that your red blood cells are similar in size.

A high RDW means that there’s variation in the size of your red blood cells

A high RDW may be a sign of anemia or a related condition