Which laboratory test determines the number of blood cells and measures hemoglobin and hematocrit?

• A. Complete blood count
• B. Calcium test
• C. Cholesterol test
• D. Blood urea nitrogen (BUN)

Answer: (A)

The test that counts the main blood cells and includes measurements of hemoglobin and hematocrit is the complete blood count. This broad panel assesses red blood cells, white blood cells, and platelets, and it specifically reports hemoglobin levels and hematocrit percentage, which together help evaluate anemia, infections, and overall blood health. The other tests measure different substances: a calcium test looks at calcium levels, a cholesterol test totals lipids in the blood, and a BUN test reflects kidney function. So the complete blood count is the one that directly determines blood cell numbers and includes hemoglobin and hematocrit.