Macrocytic Anemias

Question 1

What are microcytic anemias (MCV <80) usually due to?

Answer 1

Lack of hemoglobin production

• Iron deficiency
• Defect in heme group / protoporphyrin ring synthesis (Sideroblastic anemia)
• Defect in the heme protein itself (Thalassemias)
• Anemia of chronic disease (Can also be normocytic)

Question 2

What are normocytic anemias (MCV 80 - 99) usually due to?

Answer 2

• Anemia of chronic disease
• Paroxysmal nocturnal hemoglobinuria
• G6PD Deficiency
• Hereditary spherocytosis

Question 3

What are macrocytic anemias (MCV >100) usually due to?

Answer 3

• B₁₂ deficiency (Malnutrition, chronic gastritis, pernicious anemia)
• Folate deficiency (Malnutrition, alcoholism, chemotherapy)