Pernicious anemia is a type of anemia that occurs when the body cannot properly absorb vitamin B12, leading to a decrease in red blood cells. It is an autoimmune condition that affects the mucosal lining of the stomach and nerve cells, causing the immune system to produce antibodies that attack cells in the stomach. This attack affects the bodys ability to absorb vitamin B12, which is necessary for the production of red blood cells that carry oxygen throughout the body.

Pernicious anemia can be asymptomatic for several years before noticeable changes occur in the body. Symptoms of pernicious anemia include weakness, fatigue, pale skin, shortness of breath, dizziness, numbness or tingling in the hands and feet, difficulty walking, and a swollen, red, or sore tongue. If left untreated, pernicious anemia can cause serious medical issues, including irreversible damage to the nervous system.

Healthcare providers treat pernicious anemia by prescribing vitamin B12 supplements. The diagnosis of pernicious anemia can be challenging for clinicians due to its complexity, broad spectrum of clinical presentation, and limitations of the currently available diagnostic tests. Pernicious anemia is a relatively rare condition, with a prevalence of less than 1% in populations of European ancestry.