CBC Analysis
Patient Info
CBC Values
Frequently Asked Questions
How do I approach anemia using MCV?
MCV classifies anemia into three categories: Microcytic (MCV <80): Think iron deficiency (most common), thalassemia, anemia of chronic disease, sideroblastic anemia. Check iron studies first. Normocytic (MCV 80-100): Think acute blood loss, anemia of chronic disease, CKD (check EPO), mixed deficiency, bone marrow disorders. Macrocytic (MCV >100): Think B12/folate deficiency, alcohol use, medications (methotrexate, hydroxyurea, AZT), hypothyroidism, MDS, liver disease.
When should I worry about leukocytosis or leukopenia?
Leukocytosis (WBC >11): Infection is the most common cause. Consider stress response, medications (steroids, lithium), smoking, and malignancy (CML if WBC >50 with left shift). Leukopenia (WBC <4): Consider viral infections, medications (chemotherapy, methotrexate, carbamazepine), autoimmune (lupus), nutritional deficiency (B12, folate), and bone marrow disorders. Neutropenia <1.5 increases infection risk; <0.5 is severe and requires urgent evaluation.
What does RDW tell me and when is it useful?
RDW (red cell distribution width) measures variation in red blood cell size (anisocytosis). Normal is 11.5-14.5%. Elevated RDW helps distinguish: Iron deficiency (high RDW) from thalassemia trait (normal RDW) in microcytic anemia. Early B12/folate deficiency (high RDW) from other macrocytic causes. Mixed deficiency states (iron + B12). RDW is also an independent prognostic marker in heart failure and sepsis.