Medically reviewed by Gagandeep Brar, MD Key Takeaways Talk to your doctor if you have signs of anemia, such as excessive fatigue, because it may be helpful to have a red cell distribution width (RDW) ...

An MCV test measures the average size and volume of your red blood cells. Low MCV suggests microcytic anemia, with red blood cells smaller than normal. High MCV suggests macrocytic anemia, with red ...