What is the importance of complete blood count? Why CBC test is used?

For knowing about the types and the amount of cells prevalent in your blood, your doctor recommends the complete blood count test for you. The white blood cells, the red blood cells and the platelets are the major components being checked in your blood.The symptoms like fatigue, bruising or weakness are analysed by getting the CBC test done. CBC is also important for diagnosing diseases like anemia, other disorders and infections.

Let’s find out why is the CBC test important? It’s an important test for

Checking the White Blood Cell, Leukocyte, count

Whenever a Virus, Bacteria or any other organism attacks your body, the white blood cells fight against the same to be able to protect your body from getting the infection. White Blood cells multiply very quickly when your body gets a bacterial infection. So, too many or too less white blood cells help in finding if there is an infection in the body or else if there is a toxic reaction to the medicines or else if there is cancer of blood cells called Leukemia.

Hence a complete blood count can effectively measure overall health.

For finding an infection being prevalent in the body, the white blood cells’ count is tested. This test is also used to check the response of the body to the treatment of Cancer.

Checking the Red blood cell, RBC, count –

RBCs are Oxygen carriers from the lungs to the body. So, when the body does not get enough Oxygen, the individual’s count of the RBC is low and the individual is supposed to be suffering from the disease, anemia. If the count of the Red Blood cells is more than the required number, there are chances of the red blood cells to combine together and cause the blockage in the tiny blood vessels.Blockage of the blood vessels is called polycythaemia. In this disease the Oxygen level reduces because the RBCs are unable to carry the Oxygen.

Checking the Haemoglobin (Hgb) –

The red blood cells are full of hemoglobin molecules. Hemoglobin is extremely important for not only carrying the oxygen but also providing the red colour to the blood. This test reveals the capability of the blood to carry the Oxygen throughout the body.

Checking the Red blood cell indices –

Three types of indices of the Red Blood Cells exist- mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV), and mean corpuscular haemoglobin concentration (MCHC).



The size of the RBC becomes prominent through MCV. The concentration of HB in the blood is measured by the MCHC. Both the tests are used for checking the type of anemia a person is suffering from. Also, to know whether all the cells are exact or differ from each other, red cell distribution width test is done. All these tests are done using a machine.

Checking the Platelets or Thrombocytes –

Platelets are very important for ensuring the clotting. When the bleeding does not stop, it’s obvious that the platelet count in the body is low. When the platelet count is very high, there are chances of the formation of a blood clot in the blood vessel. A disease called as Atherosclerosis might occur because of having excessive platelets in the body.

Why CBC test is recommended?

Now let’s read the reasons for the doctors to recommend the CBC test:

• For finding the reasons behind weight loss, fever, weakness or bruising
• For finding if a person is suffering from anemia or not
• For finding the amount of blood loss from the body if the bleeding doesn’t stop
• For checking if an infection in the body is prevalent or not
• For finding if the person is suffering from Leukemia or not
• For finding the body’s reaction to the radiation treatment
• For screening the values of the blood count before the surgery
• For finding if the person is allergic or not

A complete blood count test is a very common and a very general health test and it is used to acquire valuable information about your health.