The CBC test is usually one of the first tests a doctor will run on a patient when presented with a new condition or range of symptoms. This is one of the most common tests done today. A simple blood test requiring only the equivalent of two teaspoons of blood, it is a quick and easy way to get many answers in advance of other testing.
The CBC Test
The complete blood count test is done by wiping the arm with an alcohol pad. Rubber strips may be placed above the elbow to ensure increased blood pooling in veins for easier draws. A needle is then fed into a vein, and either extracted via a syringe or through a vacuum draw into a vial. The rubber strip, if used, is removed. The needle will be withdrawn under a cotton swab to ensure pressure is given for ease of pain and easier clotting. Tape will be put over the cotton swab to stop the bleeding from the needle prick. This tape and swab can be removed in fifteen to twenty minutes when blood should have clotted and blood flow from wound has ceased.
CBC Inclusions
The complete blood count test will include these items for analysis:
- Red blood cell count, or the RBC. Counts the number of red blood cells.
- Red blood cell distribution width, or RDW. Measures the size variation of the red blood cells.
- Platelet count. Counts the platelets.
- Mean platelet volume, or MPV. Measures the size of the platelets.
- White blood cell count, or WBC. Counts the number of white blood cells.
- White blood cell count differential. Counts the amount of each classification of the white blood cells (there are five: neutrophils, basophils, eosinphils, monocytes, and lymphocytes).
- Hemoglobin, or Hb. Counts the amount of hemoglobin in the blood.
- Hematocrit, or Hct. Measures the percentage of red blood cells.
- Mean corpuscular volume, or the MCV. Measures the size of the red blood cells.
- Mean corpuscular hemoglobin concentration, or MCHC. Measures the concentration of hemoglobin in the red blood cell.
- Mean corpuscular hemoglobin, or MCH. Measures the amount of hemoglobin in the red blood cell.
CBC Normal Values
These are the normal value ranges for the items that the complete blood count test analyzes.
- RBC – Normal results are 4.2 million to 5.9 million cells/cmm.
- RDW – Normal results are 11 to 15.
- Platelet count – Normal results are 150,000 to 400,000.
- WBC – Normal results are 4,300 to 10,800/cmm.
- Hb – Normal results are varied by the gender of the patient. Males are 13 to 18 grams/deciliter. Women are 12 to 16 grams/deciliter.
- Hct – Normal results are varied by the gender of the patient. Males are 45% to 52%. Women are 37% to 48%.
- MCV – Normal results are 80 femtoliters to 100 femtoliters.
- MCHC – Normal results are 32% to 36%.
- MCH – Normal results are 27 picograms to 32 picograms.
This is a quick and simple diagnostic test that shows the healthcare provider if the patient has infection, inflammation, bleeding, bone marrow issues, or anemia. It is a thumbnail sketch of what is going on in the body at any given time and is one of the quickest ways to figure out what the next step to take in the diagnostic procedure.
 |
