What is a blood test that measures the levels of red blood cells, white blood cells, hemoglobin, hematocrit, and platelets?

• A. Hematology screen
• B. Complete blood count (CBC)
• C. Comprehensive metabolic panel
• D. Platelet function test

Answer: (B)

The main idea is that a complete blood count is the standard test that reports the major cellular components of blood in one panel. It counts red blood cells and white blood cells, and provides measurements for hemoglobin and hematocrit, as well as the number of platelets. This combination is what clinicians rely on to assess blood health, detect anemia, monitor infections or inflammation, and evaluate clotting potential. Other tests focus on different aspects: a metabolic panel looks at chemical substances and organ function rather than cell counts; a platelet function test checks how platelets work rather than how many there are; a hematology screen may cover similar areas in some settings but the test that universally reports all five components together is the complete blood count.