Normocytic Anemia – Differential Diagnosis

Normocytic anemia. Normocytic anemia refers to anemia (Hb < 12 g/dL in women, Hb < 13 g/dL in men) in which the mean cell volume is between 80 fL and 100 fL. The first branch point in the diagnostic algorithm is whether the reticulocyte count is appropriate (> 120 x 109/L) or inappropriate (< 120 x 109/L) in the setting of anemia. Note that an appropriate reticulocyte response may be normocytic or macrocytic. An appropriate reticulocyte response suggests the presence of either hemolysis or blood loss. An inappropriate reticulocyte response points to anemia of inflammation (about 80% of such cases will be normocytic, the remainder microcytic), liver disease (some cases present with macrocytosis and/or other cytopenias), kidney disease, endocrinopathy (hypothyroidism may also present with macrocytosis, and hyperthyroidism with microcytosis), or primary bone marrow disorders (which may or not be associated with other cytopenias). Nutritional deficiencies – iron deficiency, vitamin B12 deficiency and folate deficiency – may present with normocytic, normochromic indices, especially during early stages of the condition.

Pictorial of normocytic anemia.