CBC
Formal Definition
Complete blood count: a standard blood test reporting red blood cell count and indices (hemoglobin, hematocrit, MCV), white blood cell count and differential, and platelet count.
How It's Used on the Ward
"Grab a CBC" — ordered reflexively on almost every admission and as a first-line check for infection, anemia, or bleeding.
Example
""CBC shows Hgb 6.8, WBC 18.4 with 85% neutrophils, plts 420 — anemia, leukocytosis, elevated inflammatory markers. Source search started, type and screen sent.""
Clinical Context
A CBC with differential gives more data than a CBC alone — the differential tells you if leukocytosis is neutrophilic (bacterial infection, stress response) vs. lymphocytic (viral) vs. eosinophilic (allergy, parasites, malignancy). MCV guides anemia workup: microcytic (iron deficiency, thalassemia), normocytic (anemia of chronic disease, acute blood loss), macrocytic (B12/folate deficiency, alcohol, liver disease).