In this Article

• What is pernicious anemia?
• What is megaloblastic anemia?
• What causes pernicious anemia?
• Is pernicious anemia the same as vitamin B-12 deficiency anemia?
• What are the symptoms of vitamin B-12 deficiency/pernicious anemia?
• How is pernicious anemia/vitamin B-12 deficiency diagnosed?
• What is the treatment for pernicious anemia/vitamin B-12 deficiency?
• Can pernicious anemia/ vitamin B-12 deficiency be prevented?
• What is the prognosis for pernicious anemia/ vitamin B-12 deficiency?
• Pernicious Anemia At A Glance
• Patient Discussions: Pernicious Anemia - Symptoms At Onset Of Disease
• Pernicious Anemia Glossary
• Pernicious Anemia Index

What causes pernicious anemia?

Pernicious anemia is considered to be an autoimmune disease, in which the body's own immune system mistakenly damages its own tissues. It is believed that the decreased absorption of vitamin B-12 from the gastrointestinal tract in pernicious anemia results from the presence of an autoantibody against intrinsic factor (IF), a protein made in the stomach that is necessary for the absorption of vitamin B-12. Normally, vitamin B-12 binds to intrinsic factor in the stomach, and this facilitates its absorption by the small intestine further along in the digestive process. Along with the autoimmune process that attacks the IF protein and lowers IF levels in stomach secretions, another autoimmune reaction against the stomach lining cells also occurs, resulting in a form of inflammation known as chronic atrophic gastritis.

Pernicious anemia is sometimes associated with other autoimmune diseases such as Graves' disease, Hashimoto's thyroiditis and vitiligo (depigmentation or blanching of skin areas).

Is pernicious anemia the same as vitamin B-12 deficiency anemia?

Pernicious anemia is one form of vitamin B-12 deficiency that results from the autoimmune process described above. However, other causes of vitamin B-12 deficiency can also produce the same signs and symptoms as pernicious anemia. Other potential causes of vitamin B-12 deficiency include surgical removal of the stomach or a portion of the stomach (total or partial gastrectomy), other gastrointestinal diseases such as celiac disease or Crohn's disease, infections of the gastrointestinal tract, and poor nutrition.

Pernicious Anemia - Symptoms At Onset Of Disease

The MedicineNet physician editors ask:

The symptoms of pernicious anemia can vary greatly from patient to patient. What were your symptoms at the onset of your disease?

Comment submissions for this question have ended.
See 21 Viewer Comments

View Comments

Suggested Reading by Our Doctors

• cyanocobalamin-injection, Cobal, Cyanoject, Cyomin, Vibal, Vitamin B-12 - Consumer information about the medication CYANOCOBALAMIN - INJECTION (Cobal, Cyanoject, Cyomin, Vibal, Vitamin B-12), includes side effects, drug interactions, recommended dosages, and storage information. Read more about the prescription drug CYANOCOBALAMIN - INJECTION.
• Complete Blood Count (CBC) - A complete blood count (CBC) measures the concentration of white blood cells, red blood cells, and platelets in the blood and aids in the diagnosis of conditions and diseases such as anemia, malignancies, and immune disorders.
• Stomach Cancer - Read about stomach cancer symptoms, causes, stages, gastric cancer statistics, diagnosis, surgery, other treatment types and risk factors, like H. pylori.

Read more Pernicious Anemia related articles »

Latest Medical News

• Health Tip: When Dementia Is Treatable