by Kahn M
(Juvenile Pernicious Anemia; Congenital Pernicious Anemia; Biermer Disease; Addisonian Anemia)


Anemia is a low level of healthy red blood cells (RBCs). RBCs carry oxygen from the lungs to the rest of the body. When RBCs are low the body does not get enough oxygen.

The sooner pernicious anemia is treated, the better the outcome.

Red Blood Cells
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Pernicious anemia is caused by a problem with the body taking in vitamin B12. This vitamin is needed to make healthy RBCs. Over time the amount of new RBCs will drop if vitamin B12 levels are low. There are many reasons the body could have problems taking in vitamin B12. They are:

  • Inflammation of the stomach—atrophic gastritis
  • The immune system starts attacking:
    • A protein called intrinsic factor that the body needs to take in vitamin B12
    • Cells that make both intrinsic factor and hydrochloric acid in the stomach
  • Removal of all or part of the stomach
  • Medicines that block B12 from being used in the body
  • Genetic issues

Risk Factors

Pernicious anemia is more common in people over 50 years old. It is also more common in people whose families come from northern European or Scandinavia. Other things that may increase the risk are having:


Symptoms may change or get worse over time. A person with pernicious anemia may have:

  • Feeling of pins and needles in their feet or hands
  • Diarrhea and weight loss
  • Stinging feeling on the tongue, or a smooth red tongue
  • Fatigue, feeling weak, or lightheadedness
  • Paleness
  • Problems smelling or tasting
  • Confusion or trouble focusing
  • Depression or irritability
  • Problems with balance
  • Heart beats faster than usual


The doctor will ask about symptoms and past health. A physical exam will be done. A blood test will show low levels of RBCs. Other blood tests will also show low levels of proteins, vitamins, and other items needed to build RBCs. More tests may be done to see why vitamin B12 levels are low.


The goal of treatment is to get RBC levels back to normal. This can be done by boosting vitamin B12 levels. This should help make more RBCs and ease the anemia. Treatment may include:

  • Vitamin B12 that may be given as:
    • Shots into a muscle—to bypass the stomach if it cannot take in the vitamin.
    • B12 pills—may be taken by mouth with the injections. This may be more common for older adults to boost how much B12 gets into the body.
    • Intranasal—a nose spray that may help those who cannot get shots.
  • Iron supplement pills—if there are low levels of iron. Iron is also needed to make RBCs.


There is no way to prevent pernicious anemia.


Family Doctor—American Academy of Family Physicians 

National Institutes of Health Office of Dietary Supplements 


Health Canada 

The College of Family Physicians of Canada 


Pernicious anemia. EBSCO DynaMed website. Available at: Accessed May 16, 2022.

Vitamin B12. National Institutes of Health Office of Dietary Supplements website. Available at: Accessed May 16, 2022.

Vitamin B12-deficiency anemia. National Heart, Lung, and Blood Institute website. Available at: Accessed May 17, 2022.

Revision Information

  • Reviewer: EBSCO Medical Review Board Marcin Chwistek, MD
  • Review Date: 03/2022
  • Update Date: 05/17/2022