Understanding Low RDW: Causes, Symptoms & What It Means

Red cell distribution width (RDW) is a measure of the variation in the size of red blood cells. A high RDW indicates that there is a greater variation in size than is normal, while a low RDW indicates that the red blood cells are more uniform in size.

A low RDW may be seen in a number of conditions, including:

* Iron deficiency anemia

* Vitamin B12 deficiency

* Folate deficiency

* Thalassemia

* Sickle cell anemia

* Some types of leukemia

* Some types of lymphoma

A low RDW is not typically a cause for concern, but it may be an indication of an underlying medical condition. If you have a low RDW, your doctor may recommend further testing to determine the cause.