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Macrocytosis/Macrocytic anemia

Stanley L Schrier, MD
Section Editor
William C Mentzer, MD
Deputy Editor
Jennifer S Tirnauer, MD


Macrocytosis is a descriptive term for red blood cell (RBC) size larger than the normal range. It may be caused by abnormalities of RBC production in the bone marrow, altered RBC membrane composition, or an increase in the percentage of reticulocytes, which are larger than mature RBCs. This topic discusses causes of macrocytosis and macrocytic anemia. Additional topics discuss the following:

Microcytosis/microcytic anemia – (See "Microcytosis/Microcytic anemia".)

General anemia evaluation

Child – (See "Approach to the child with anemia".)

Adult – (See "Approach to the adult patient with anemia".)


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Literature review current through: Sep 2016. | This topic last updated: May 11, 2016.
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