Select hemoglobin, MCV, reticulocyte count, smear findings, bleeding history, diet, and systemic symptoms → differentiate iron deficiency, thalassemia trait, hemolytic anemia (G6PD, spherocytosis, AIHA), acute blood loss, megaloblastic anemia, or bone marrow failure (aplastic, leukemia).
⚠️ Red flags: severe pallor, tachycardia, hypotension, heart failure → urgent transfusion. Pancytopenia + fever → sepsis risk in aplastic anemia / leukemia.
Select hemoglobin level, MCV (microcytic, normocytic, macrocytic), reticulocyte count (↑ hemolysis, ↓ marrow failure), smear abnormalities (spherocytes, schistocytes, target cells, bite cells), bleeding history, diet, and family history → differentiate iron deficiency, thalassemia, hemolytic anemia, acute blood loss, B12/folate deficiency, or aplastic anemia.