NHA Phlebotomy Certification Practice Exam

Which of the following tests is not part of a complete blood count (CBC)?

1. Red blood cell count

2. Platelet count

3. Sedimentation rate

4. Differential

The correct answer is: Sedimentation rate

A complete blood count (CBC) is a comprehensive test that evaluates various components of blood, including the elements that indicate the overall health of an individual. It includes measurements such as the red blood cell count, which indicates the number of red blood cells present and helps assess conditions like anemia; platelet count, which is crucial for evaluating blood clotting factors; and the differential count, which provides a breakdown of different types of white blood cells present in the blood, helping to diagnose infections and immune disorders. The sedimentation rate, on the other hand, is not included in a CBC. It is a separate test used to measure the rate at which red blood cells settle at the bottom of a test tube, which can help assess inflammation in the body, but it does not provide direct information regarding the blood components encompassed by a CBC. Thus, recognizing the functions and purposes of the various tests illustrates why the sedimentation rate does not belong to a complete blood count.