Pernicious anemia

Pernicious anemia is a type of anemia caused by the body’s inability to absorb vitamin B12, leading to insufficient production of healthy red blood cells. This condition is often due to an autoimmune response that destroys intrinsic factor, a protein necessary for vitamin B12 absorption.

• Anemia-related symptoms: Fatigue, dizziness, shortness of breath, headache, pale skin, and cold hands and feet.
• Vitamin B12 deficiency symptoms: Muscle weakness, loss of reflexes, tingling and numbness in the hands and feet, balance problems, difficulty walking, and weakened bones.

Iron deficiency anemia and autoimmune endocrine disorders, such as: Addison’s disease, type 1 diabetes, Graves’ disease, vitiligo.

A positive family history is associated with pernicious anemia. Surgical removal of parts of the stomach or small intestine can also cause the disease. Other risk factors for the vitamin B12 deficiency in pernicious anemia are the use of certain medications, and a vegetarian diet without the use of vitamin B12 supplements. It is a rare condition, with an estimated prevalence of less than 1% in populations of European ancestry.

• Addressing the Gaps in the Vitamin B12 Deficiency 2024 NICE Guidelines: Highlighting the Need for Better Recognition, Diagnosis, and Management of Pernicious Anaemia (2025)
• Pernicious Anemia: The hematological presentation of a multifaceted disorder caused by cobalamin deficiency (2022) 
• Autoimmune gastritis, with or without pernicious anemia: epidemiology, risk factors, and clinical management (2021)
• Pernicious anemia: Pathophysiology and diagnostic difficulties (2021)
• Genome-wide association study identifies five risk loci for pernicious anemia (2021)