Anemia: Classification

Types of anemia (classified by MCH and MCV)

Hypochromic anemia (microcytic anemia; MCH ↓ → hypochromic; MCV↓ → microcytic).

  • Iron deficiency anemia [ferritin ↓↓; serum iron ↓↓; transferrin ↑↑]
  • Other hypochromic anemias: [ferritin: normal to ↑]
    • Iron utilization disorders
    • Inflammatory anemia/infectious anemia/tumor anemia [ferritin ↑; serum iron ↓↓; transferrin ↓]
    • Hemoglobinopathies (diseases caused by disorders of hemoglobin).
    • Myelodysplastic syndrome [ferritin ↑↑; serum iron ↑↑; transferrin ↓↓]
    • Sideroblastic anemias (increased sideroblasts are present in the bone marrow smear; this is the sign of impaired iron utilization, resulting in ineffective erythropoiesis (formation and development of erythrocytes/red blood cells)).
    • Thalassemia [beta-thalassemia: ferritin normal to ↑; serum iron normal to ↑; transferrin normal to ↓).

Normochromic anemia (normocytic anemia; MCH normal → normochromic; MCV normal → normocytic).

  • Normochromic, normocytic anemia + reticulocyte count ↑
    • Acute hemorrhage (hemorrhage anemia).
    • Hemolytic anemia
  • Normochromic, normocytic anemia + reticulocyte count normal to ↓
    • Endocrinological causes:
      • Eunuchoidism
      • Hypo- and hyperthyroidism (hypo- or hyperthyroidism, respectively).
      • Liver disease
      • M. Addison’s disease (adrenocortical insufficiency)
      • Renal insufficiency (renal dysfunction; renal anemia).
      • Panhypopituitarism (deficiency or an absence of all hormones produced in the anterior pituitary gland).
    • Normochromic, normocytic anemia + reticulocyte count normal to ↓ + serum iron normal to ↑
    • Normochromic, normocytic anemia + reticulocyte count normal to ↓ + serum iron ↓
      • Early iron deficiency anemia

Hyperchromic anemia (macrocytic anemia; MCH ↑ → hyperchromic; MCV ↑ → macrocytic) / megaloblastic anemia.

  • Serum folic acid or B12 concentrations ↓
  • Folic acid or B12 concentrations in serum normal.
    • Chronic liver disease
    • Chronic kidney disease
    • Chronic inflammatory diseases
    • Intoxications (poisonings)

Hemolytic anemia

Hemolytic anemia (MCH normal → normochromic; MCV ↑ → macrocytic; elevated are: Urinary urobilin (dark urine), indirect bilirubin, LDH, HBDH, iron, free hemoglobin, reticulocytes, and ESR (erythrocyte sedimentation rate); decreased: haptoglobin).