What is pernicious anemia?

Pernicious anemia is a condition in which the body produces insufficient numbers of red blood cells because the intestines cannot absorb vitamin B12 properly. Vitamin B12 is essential for the production of red blood cells in the bone marrow. This disorder occurs due to low levels of a protein called intrinsic factor, which is released by stomach cells and is necessary for the absorption of vitamin B12 in the intestines.

The inability to produce intrinsic factor may be inherited or may arise from an autoimmune process, in which the body’s immune system attacks its own tissues, in this case, specialized mucosal cells in the lining of the stomach. Pernicious anemia can also develop from other conditions affecting the stomach lining, such as atrophic gastritis (inflammation and thinning of the stomach lining). Pernicious anemia is more common in people with Northern European or Scandinavian ancestry, and the average age of onset of symptoms is 60 years (Source: PubMed Health).

Pernicious anemia leads to reduced levels of oxygen in the body, which can produce generalized symptoms, such as fatigue, weakness, and shortness of breath. Left untreated, pernicious anemia can cause permanent damage to the nervous system. Fortunately, pernicious anemia can be treated successfully.

Treatment for pernicious anemia includes vitamin B12 supplementation, which is administered through injection. Oral vitamin B12 supplements are not absorbed well because patients with pernicious anemia lack adequate intrinsic factor in the stomach lining. Treatment with vitamin B12 injections can prevent the permanent neurological damage that may result from deficiency of this vitamin.

Seek prompt medical care if you experience persistent or serious symptoms of neurological damage associated with pernicious anemia, including confusion, changes in behavior or personality, loss of balance, or memory loss. You should also seek medical care for persistent symptoms of pernicious anemia, such as shortness of breath, dizziness, or fatigue.


What are the symptoms of pernicious anemia?

Symptoms of pernicious anemia include general fatigue and weakness, digestive symptoms such as constipation or diarrhea, and neurological symptoms such as confusion, depression, loss of balance, or numbness. Neurological symptoms are serious and may indicate persistent anemia that should be treated promptly.

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What causes pernicious anemia?

Pernicious anemia is caused by the lack of a protein called intrinsic factor. This protein, which is produced by cells in the stomach lining, is essential for proper absorption of dietary vitamin B12 in the intestines. Low levels of intrinsic factor are often the result of an autoimmune condition, in which the body produces antibodies that attack its own stomach cells. Rarely, infants are born ... Read more about pernicious anemiacauses


How is pernicious anemia treated?

For most patients with pernicious anemia, the condition is readily treated, and the prognosis is excellent. Treatment of pernicious anemia involves the administration of vitamin B12 injections, typically on a monthly basis. In some cases, taking very high doses of vitamin B12 supplements by mouth may be effective, although in general, low levels of intrinsic factor limit the absorption of oral ... Read more about pernicious anemiatreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 20, 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