MedlinePlus Medical Encyclopedia: Megaloblastic anemia

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Megaloblastic anemia

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Megaloblastic anemia - view of red blood cells

Hypersegmented PMN (Close-up)

Blood cells

Alternative names Return to top

Anemia - megaloblastic

Definition Return to top

Megaloblastic anemia is a blood disorder characterized by anemia, with red blood cells that are larger than normal, usually resulting from a deficiency of folic acid or of vitamin B-12.

Causes, incidence, and risk factors Return to top

Deficiencies of vitamin B-12 and folic acid are the most common causes of megaloblastic anemia. Other causes are leukemia, myelofibrosis, multiple myeloma, certain hereditary disorders, drugs that affect DNA synthesis such as chemotherapy agents (methotrexate), alcohol, and other causes. Risk factors relate to the causes. (See also pernicious anemia).

Symptoms Return to top

Loss of appetite
Diarrhea
Tingling and numbness of hands and feet
Pale skin color
Tiredness
Headaches
Sore mouth and tongue
Change in skin color

Signs and tests Return to top

Examination of neurological signs may show abnormal reflexes, decreased position sense, and decreased vibration sense if related to vitamin B-12 deficiency.

Tests include:

Complete blood count (shows anemia with large red blood cells)
Bone marrow examination
Serum B-12
Schilling test (may identify poor absorption as cause of vitamin B-12 deficiency)
Serum folate

Treatment Return to top

The objective of treatment is to determine the cause of the anemia, and the treatment depends upon the cause. Anemias related to vitamin deficiencies are discussed separately.

Expectations (prognosis) Return to top

The outcome is expected to be good with treatment.

Complications Return to top

Complications vary with the underlying cause.

Calling your health care provider Return to top

Call for an appointment with your health care provider if symptoms develop.

Prevention Return to top

Adequate intake of vitamin B-12 and folic acid is helpful.

Update Date: 5/2/2003

Updated by: Ezra E. W. Cohen, M.D., Section of Hematology/Oncology, Department of Medicine, The University of Chicago, Chicago, IL. Review provided by VeriMed Healthcare Network.

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