The most common blood evaluation test undertaken is the CBC blood test. The test helps to measure the concentration of red blood cells, white blood cells, and platelets in the blood. The following HealthHearty article will help explain what is complete blood count test.
A CBC blood test or complete blood count is a very important blood test that provides information related to the kind and number of cells in the blood. It helps in measuring the different components of blood like the red blood cells, white blood cells and even platelets. The CBC blood count is also called the full blood count (FBC), full blood exam (FBE) or blood panel. This test is recommended by a doctor to get information regarding the cells in the patient’s blood.
What is a CBC Blood Test?
The blood contains three types of cell like the leukocytes, erythrocytes, and thrombocytes. When an abnormally high or low blood count is encountered, it helps in indicating different diseases. Thus, a blood count is routinely performed to help understand the different infections a patient might be suffering from. This is a routine test that is performed during all physical examinations.
Fasting for CBC Test
You need not stay on an empty stomach before giving your blood sample, if you are going in for only a complete blood count. However, if you need to go in for additional test(s) along with the CBC test, then your doctor may ask you to fast, and will provide you with the necessary instructions regarding that. Some of the additional tests (that require fasting) may include fasting glucose, fasting triglycerides, fasting lipids or glucose tolerance tests. For such tests, a patient is expected to fast for about 12 hours before undergoing the test. Once the test is done, your doctor will give you specific instructions regarding how to resume your normal meals.
The test is performed to measure the following blood components:
- The number of RBCs
- The number of WBCs
- Hemoglobin levels in blood
- Number of red blood cells making up the volume of whole blood
The test also helps measure the average blood cell size (MCV), the amount of hemoglobin per red blood cell (MCH), the hemoglobin amount relative to size of cell per red blood cell (MCHC).
Test Results Explained
The test covers a number of parameters that help the doctors diagnose various infections or diseases. The complete blood count results explained in the following paragraphs will help you understand the test better.
White Blood Cell Count
The white blood cell count or WBC count is the most important parameter to spot an infection. WBC count also helps in detection of certain types of leukemia or blood cancer. When there is low WBC count, it indicates bone marrow disease or an enlarged spleen. HIV patients also have low white blood cell counts in some cases. High WBC count indicates infection, inflammation, stress, etc. in the body.
Red Blood Cell Count
The red blood cell count or RBC count consists of test that includes mean red cell volume (Mean Corpuscular Value), hematocrit and hemoglobin (Hgh) test. MCV measurements help in detection of anemia, that is seen when there is low RBC count in the body. Low hematocrit range or low hemoglobin count also indicates failure of bone marrow to produce blood, internal destruction of blood cells, etc. High hemoglobin levels indicate excessive blood cell production by bone marrow, a patient living at high altitudes or lung diseases.
The platelets are very important cells that help in clotting of blood and prevention of hemorrhage. These platelets clump together and plug the damaged blood vessel forming blood clots. When the platelet count (PLT) is too low, it indicates that the patient is on risk of developing bleeding in any part of the body. Low platelet count also occurs due to premature destruction states like acute blood loss, side effects of drugs like heparin, infection with sepsis, Immune Thrombocytopenia (ITP), enlarged spleen, bone marrow failure due to myelofibrosis or leukemia.
Normal Result Value for CBC Blood Test
The normal results of complete blood count may vary from individual to individual. It may even vary in different laboratories. It is always best to speak to your doctor for the correct interpretation of the CBC blood test.
- RBC Count: Male: 4.7 to 6.1 million cells/mcL
- Female: 4.2 to 5.4 million cells/mcL
- WBC Count: 4, 500 to 10, 000 cells/mcL
- Hematocrit: Male: 40.7 to 50.3 %
- Female: 36.1 to 44.3 %
- Hemoglobin: Male: 13.8 to 17.2 gm/dL
- Female: 12.1 to 15.1 gm/dL
- MCV: 80 to 95 femtoliter
- MCH: 27 to 31 pg/cell
- MCHC: 32 to 36 gm/dL
Key: cells/mcL = cells per microliter; gm/dL = grams per deciliter; pg/cell = picograms per cell.
The CBC blood test cost is about 25 to 50 USD depending upon the laboratory you choose for testing your blood sample. This test is very useful in detection of any kind of infection, blood cancer, stress, anemia, deficiency of nutrients, inflammatory disease, bone marrow failure, autoimmune diseases, emotional or physical stress, malnutrition, hemolysis, multiple myeloma, hemorrhage, etc.