Diagnostic Evaluation of Anemia Based on Presumed Etiology

Classification of Anemia

Anemia is classified into three major types based on mean corpuscular volume (MCV):

• Microcytic Anemia: Characterized by an MCV of <80 fL. Common causes include iron deficiency, thalassemia, and anemia of chronic disease.
• Normocytic Anemia: MCV ranges between 80-100 fL. Causes include acute blood loss, hemolysis, and anemia of chronic disease.
• Macrocytic Anemia: MCV >100 fL. This type is often associated with vitamin B12 or folate deficiency, alcoholism, and myelodysplastic syndromes.

Diagnostic Approach

A systematic diagnostic approach includes:

• Patient History & Clinical Symptoms: Fatigue, pallor, dyspnea, and tachycardia.
• Laboratory Tests: Complete blood count (CBC), reticulocyte count, peripheral blood smear, iron studies, and vitamin B12/folate levels.
• Bone Marrow Examination: Indicated in cases of unexplained anemia or suspected bone marrow failure syndromes.

Treatment Considerations

Treatment depends on the underlying cause:

• Iron supplementation for iron deficiency anemia.
• Vitamin B12 or folate replacement for macrocytic anemia.
• Management of chronic disease or hemolysis in normocytic anemia.