Pernicious Anemia

Pernicious anemia is a chronic autoimmune condition in which the body cannot absorb enough vitamin B12, a vital nutrient required to make healthy red blood cells. The immune system attacks the stomach lining and intrinsic factor, a protein necessary for B12 absorption in the small intestine. Without B12, the body cannot make enough healthy red blood cells, which leads to anemia and sometimes nerve damage if left untreated.

Blood and energy-related: Fatigue; Weakness; Pale or yellowish skin; Shortness of breath; Dizziness. Neurological symptoms (due to prolonged B12 deficiency): Numbness or tingling in hands and feet; Poor balance or coordination; Memory issues or brain fog; Mood changes or depression. Digestive or other signs: Swollen, sore tongue (glossitis); Mouth ulcers; Loss of appetite; Weight loss.

Caused by an autoimmune attack on parietal cells in the stomach (which produce intrinsic factor) and intrinsic factor itself. Without intrinsic factor, vitamin B12 from food cannot be absorbed properly. Other risk factors include family history of autoimmune diseases, type 1 diabetes, Hashimoto's, or vitiligo, older age, and Northern European ancestry.

Complete blood count (CBC) - shows large red blood cells (megaloblastic anemia); Vitamin B12 level - low in the blood; Intrinsic factor antibody test - often positive; Parietal cell antibody test; Methylmalonic acid (MMA) and homocysteine - often elevated.

Vitamin B12 injections - often given regularly for life; High-dose oral B12 supplements (in some cases); Monitoring for neurological symptoms; Treating underlying autoimmune gastritis if present. Early treatment often leads to full recovery.

Excellent with early treatment. Neurological symptoms may become permanent if untreated for too long. Long-term B12 maintenance therapy is needed. May be linked to higher stomach cancer risk, so ongoing care is important.

Affects approximately 0.1% of the general population, up to 2% in people over 60. More common in Northern Europeans, women, and people with autoimmune disorders.