Pernicious Anemia: Hematology Review

Young female nurse in a mask drawing blood from a female patient pernicious anemia title card

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  1. Pernicious Anemia Pathophysiology
  2. Pernicious Anemia Nursing Interventions
  3. Pernicious Anemia Memory Trick

Pernicious anemia is a type of anemia that occurs when a person’s body is unable to absorb enough vitamin B12 from the food they eat. Vitamin B12 is essential for the production of red blood cells, and a deficiency in this vitamin can lead to a decrease in the number of red blood cells in the body.

If left untreated, pernicious anemia can cause permanent damage to the nervous system and other organs in the body.

Pernicious Anemia Pathophysiology

Pernicious anemia is a condition that occurs when the body cannot absorb the essential ingredients in producing red blood cells. Red blood cells are formed inside the bone marrow.

The creation of red blood cells is uncomplicated. You just need the following ingredients:

Folate and folic acid are similar. Folate is a naturally occurring vitamin, while folic acid is created inside a laboratory and is referred to as “synthetic.”

So to yield healthy red blood cells, the body requires iron, vitamin B12, and folate or folic acid. If the body lacks any of these ingredients, the creation of red blood cells is compromised. Once this happens, the red blood cell count decreases, which can lead to anemia.


There are many reasons for a low red blood cell count that can eventually lead to anemia, some of which are bone marrow problems or insufficient B12. But the primary reason why pernicious anemia happens is due to the GI tract’s inability to absorb building blocks for red blood cell production.

Pernicious anemia does not happen out of nowhere. There’s a reason why the GI tract is unable to absorb vitamin B12, and it’s due to the gastric parietal cells.

Gastric Parietal Cells

These little cells found along the stomach lining are called parietal cells. This is one fact that you have to remember when dealing with clients who are experiencing pernicious anemia.

Parietal cells are responsible for pumping out gastric juices that break down food and are also the main culprit for the overproduction of acids that can cause gastritis, heartburn, or gastroesophageal reflux disease (GERD). Increased gastric acid can result in the deterioration or degradation of the stomach lining.


There are two primary medications given to decrease gastric acid, counteract the effects, and prevent further damage to the stomach lining:

  • H2 receptor blockers
  • Proton-pump inhibitors (PPI)

The Intrinsic Factor

The gastric parietal cells secrete intrinsic factor. Intrinsic factor is a protein that the gastric parietal cells create, which is mainly responsible for transporting vitamin B12 to be absorbed by the gastrointestinal tract.

This intrinsic factor will take vitamin B12 in the lower portions of the GI, where it would be digested and utilized. Without the intrinsic factor, the body won’t be able to absorb vitamin B12, and without vitamin B12, the body won’t create red blood cells, resulting in pernicious anemia.

Factors that Affect the Intrinsic Factor

Some factors affect the creation of intrinsic factor, including:

  • Gastritis (burning in the lining of the stomach)
  • Gastric parietal cells aren’t secreting adequately
  • Hereditary/Genetics
  • Exposure to harmful chemicals and toxins
  • Alcoholism
  • Smoking
  • Increased fat and caffeine consumption

Pernicious Anemia Nursing Interventions

Since the gastrointestinal tract is compromised (due to the burning of the stomach lining), taking medication orally is not advisable. Instead, vitamin B12 is given subcutaneously to promote proper absorption, and this is given for the rest of your client’s life. 

In addition, subcutaneous injections will help clients prevent pernicious anemia and low blood count.  

You also have to educate your client to:

  • Increase iron intake
  • Take supplemental folic acid
  • Don’t miss out on a vitamin B12 shot
  • Stay away from risk factors that cause gastritis and GERD

Lastly, pernicious anemia clients will present pale and tired due to decreased oxygen circulating throughout their body caused by low red blood cell count.

Pernicious Anemia Memory Trick 

There are different types of anemia, and it gets difficult and confusing to remember all and distinguish one from the other. 

Here’s a very handy technique to help you remember pernicious anemia the easiest way possible:

Let’s assume that you’re aware of or properly acquainted with that infamous character from The Lord of the Rings. 

“My precious,” said Gollum. 

The key to remembering pernicious anemia is to associate it with Gollum, who usually utters “My precious,” which is close to saying “pernicious.” Aside from that, this character also has a habit of rubbing his hands around his gastrointestinal (GI) tract.  

And that’s the most important determinant of what pernicious anemia is – it occurs in the GI tract.

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