Drexel University College of Medicine

Diseases and Conditions

Megaloblastic anemia

Definition

Megaloblastic anemia is a blood disorder in which there is anemia with larger-than-normal red blood cells.

Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.

Alternative Names

Anemia - megaloblastic

Causes, incidence, and risk factors

Megaloblastic anemia is usually caused by a deficiency of folic acid or vitamin B12.

Other less common causes are:

• Alcohol abuse
• Certain inherited disorders
• Drugs that affect DNA, such as chemotherapy drugs
• Leukemia
• Myelodysplastic syndrome
• Myelofibrosis

Risk factors relate to the causes.

See also:

• Anemia - B12 deficiency
• Folate-deficiency anemia
• Pernicious anemia

Symptoms

See:

• Anemia - B12 deficiency
• Folate-deficiency anemia
• Pernicious anemia

Signs and tests

For testing information, see:

• Anemia - B12 deficiency
• Folate-deficiency anemia
• Pernicious anemia

Treatment

The first goal is to diagnose the cause of the anemia. The treatment depends on the cause. Anemias related to specific vitamin deficiencies are discussed separately.

See:

• Anemia - B12 deficiency
• Folate-deficiency anemia
• Pernicious anemia

Expectations (prognosis)

  Megaloblastic anemia - view of red blood cells
  Hypersegmented PMN (Close-up)
  Blood cells

References

Antony AC. Megoblastic anemias. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 39.

Kaferie J, Strzoda CE. Evaluation of macrocytosis. Am Fam Physician. 2009;79:203-208.

Physician Reference

International Classification of Diseases, 9^th Revision (ICD9)

281.3

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Review Date: 1/31/2010
Reviewed By: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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