What is macrocytosis?

Macrocytosis, or megaloblastic anemia, is a blood condition characterized by insufficient and unusually large red blood cells. The lack of viable red blood cells leads to oxygen deficiency throughout the body. Over time, this lack of oxygen can cause symptoms related to many organ systems.

Symptoms of macrocytosis can range from very mild to severe. General symptoms of macrocytosis are related to anemia and include fatigue, poor concentration, dizziness, pallor, and shortness of breath. In severe cases, macrocytosis can lead to neurological symptoms, such as confusion, dementia, depression, loss of balance, and numbness or tingling in the arms and legs. Neurological symptoms of macrocytosis should receive prompt medical attention, as they may become permanent if not treated.

Macrocytosis typically results from a problem with deficiencies of vitamin B12 or folate, two nutrients that are essential for red blood cell formation. Such problems can result from damage to the digestive tract that interferes with efficient absorption of these nutrients. A hereditary condition called pernicious anemia, in which the body cannot absorb sufficient vitamin B12, is a major cause of macrocytosis. In addition, inadequate dietary intake of vitamin B12 and folate may lead to low levels of these nutrients in the body.

Macrocytosis can be treated with vitamin B12 supplements in pill or injection form. Following your treatment plan will prevent any severe complications from macrocytosis.

Seek prompt medical care for symptoms of macrocytosis that may be neurological in origin, such as confusion, dementia, depression, loss of balance, and numbness or tingling in hands and feet. These neurological symptoms may become permanent if not treated within six months, especially if they result from pernicious anemia.


What are the symptoms of macrocytosis?

Mild macrocytosis produces no symptoms. Symptoms of moderate macrocytosis include fatigue and weakness, problems with digestion, and neurological symptoms. Neurological symptoms, such as confusion, depression, or numbness, may indicate nerve dama... Read more about macrocytosissymptoms


What causes macrocytosis?

Usually, macrocytosis is caused by nutritional deficiency, specifically of folate or vitamin B12. This can arise from a hereditary condition called pernicious anemia, in which a protein called intrinsic factor is lacking in your gut. Intrinsic factor helps your body absorb vitamin B12. Vitamin B12 is essential for replenishing folate, which is required by your body to make red blood cells.
Read more about macrocytosiscauses


How is macrocytosis treated?

For mild cases of macrocytosis, no treatment may be required. The treatment of macrocytosis depends on its cause. For cases directly linked to vitamin B12 deficiency, injections of the vitamin can be given. For mild cases, oral supplements may be prescribed, along with a balanced diet. For cases in which macr... Read more about macrocytosistreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 6, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Heart, Blood and Circulation