Differential Diagnosis for Anemia

The following is a differential diagnosis for anemia, categorized for clarity and emphasis on potential severity.

• Single Most Likely Diagnosis

  • Iron deficiency anemia: This is the most common cause of anemia worldwide, often due to chronic blood loss (e.g., menstrual bleeding, gastrointestinal ulcers, cancer) or inadequate dietary intake of iron.

• Other Likely Diagnoses

  • Vitamin B12 deficiency anemia: Caused by a lack of vitamin B12, which is essential for the production of red blood cells. This can be due to dietary deficiency (common in vegans), malabsorption (as in celiac disease or Crohn's disease), or pernicious anemia.
  • Anemia of chronic disease: Associated with chronic infections, inflammatory conditions (e.g., rheumatoid arthritis), or malignancies. The chronic disease leads to a decrease in the production of red blood cells and a decrease in the availability of iron for erythropoiesis.
  • Folate deficiency anemia: Similar to vitamin B12 deficiency, folate is crucial for red blood cell production. Deficiency can occur due to inadequate dietary intake, increased demand (as in pregnancy), or malabsorption.

• Do Not Miss Diagnoses

  • Sickle cell anemia: A genetic disorder that affects hemoglobin production, leading to abnormally shaped red blood cells. It's crucial to diagnose due to its significant impact on health and the need for specific management strategies.
  • Thalassemia major: Another genetic disorder affecting hemoglobin production, leading to severe anemia. Early diagnosis is critical for proper management, including regular blood transfusions.
  • Acute blood loss: Although often obvious, acute blood loss (e.g., from trauma, surgery, or a ruptured aneurysm) can sometimes be occult and must be promptly identified and treated to prevent shock and death.

• Rare Diagnoses

  • Pernicious anemia: An autoimmune condition leading to a deficiency in intrinsic factor, necessary for vitamin B12 absorption. It's rare but important to diagnose due to its specific treatment requirements.
  • Paroxysmal nocturnal hemoglobinuria (PNH): A rare, acquired, life-threatening disease of the blood characterized by the destruction of red blood cells, bone marrow failure, and the potential for blood clot formation.
  • Lead poisoning: Can cause anemia by interfering with heme synthesis. It's more common in children due to ingestion of lead-containing substances but can also affect adults, especially those exposed to lead in their occupation.