A CBC, or complete blood count, is a routine test that physicians use to monitor a person’s overall health. It is the calculation of the cellular elements of blood. A special machine is required to analyze the different components, and it takes about a minute to get the results. The main goal of this test is to measure three things: the concentration of white blood cells, red blood cells, and the platelets present in the blood.
How it’s Performed
The CBC is performed by taking a couple teaspoons of blood from the patient. First, the area is cleansed with an alcohol pad. Next, a needle is inserted into the skin to draw blood. A vacuumed viral is used for collection. After the appropriate amount is drawn, it is analyzed.
This test measures the following counts:
- WBC or White Blood Count: This is the number of white blood cells in the blood’s volume. Ranges should be between 4,300 through 10,800 per cubic millimeter.
- WBC Differential Count: The differential count includes granulocytes, lymphocytes, monocytes, eosinophils, and basophils. A trained technician can use a microscope to measure the differential based on the shape and size.
- RBC or Red Blood Count: The number of red blood cells in the blood’s volume is the RBC. The rates can vary between different testing facilities, but the most common measurements are between 4.2 to 5.9 per cubic millimeter. Red blood cells are a bit smaller than the white, and there are millions of them circulating in the blood. However, they are larger than the platelets, and smaller than white blood cells.
- Hemoglobin or Hb: Hemoglobin is a molecule in red blood cells that carries oxygen. It is what gives blood its red color. For men, the hemoglobin rates should be between 12 – 15.5 grams per deciliter. For women, it should be 7.4 – 9.9 grams per deciliter.
- Hematocrit or Hct: Hematocrit is the ratio of the volume of cells to the volume of whole blood. A normal range for a man should be 45-50 percent, while the range for a woman should be 37-45 percent. A blood sample is spun down into a test tube, and it causes the red blood cells to rest at the.
- Mean Corpuscular Volume or MCV: The average volume of a red blood cell is called an MCV. This calculation is figured by taking the hematocrit and red cell count. A normal range is between 80-100 femtoliters.
- Mean Corpuscular Hemoglobin: The average amount of hemoglobin in the red blood cell is the MCH. The lab calculates the hemoglobin and red blood cell counts together to derive this value. Between 27 – 32 picograms is the normal range.
- Mean Corpuscular Hemoglobin Concentration or MCHC: The MCHC is the average concentration of hemoglobin in the volume of red cells. It is calculated from the hemoglobin and hematocrit measurement. A normal range should fall between 32-36 percent.
- Red Cell Distribution Width or RDW: The measurement of the red cell size and shape is RDW. A normal range should fall between 11-15.
- Platelet Count: Platelets are part of a cell that doesn’t have its nucleus, and there should be a specific amount in any volume of blood. They play an important in the role in blood clotting. A normal range should be between 150,000 – 400,000 per cubic millimeter.