What makes up your Complete Blood Count Test

You can be asked to do a blood test, also known in medical jargon as a complete blood count(CBC). CBC is a test that provides information about a person's blood cells, size, and quantity.

This test is relatively easy for patients. The analysis is performed by an automated hematology analyzer, which makes the results fast and cheap to obtain. The CBC is one of the most commonly performed medical tests because it provides much information on a person's general health.

How can CBC be used?

CBC can be done to monitor general health during annual checkups or to explore possible causes of symptoms. It can help diagnose medical conditions and check the health of your immune system. It can detect blood cancers, anemia, infections, and other conditions. Anemia is a good example of the importance of CBC. It can have several causes, including nutritional deficiency (iron or vitamin) or genetic disorder (sickle cell disease, thalassemia). Bone marrow failure or blood cancer can also cause anemia. Combining different elements of the CBC can help physicians understand what causes anemia.

Blood count can also help to assess the impact of some medications. CBC analysis before surgical procedures can minimize complications.

What CBC measure?

Thebloodiscomposedofplasmaandbloodcells.In a healthy person, plasma accounts for 55% of the blood. Plasma is the liquid portion of the blood, consisting of water, essential blood proteins, and nutrients.

The CBC will measure the number and size of all blood cells:

Red blood cells (erythrocytes)

White blood cells(leukocytes)

Platelets (thrombocytes)

Red Blood Cells:

Red Blood cells are the blood's most abundant cells, representing 45% of the blood volume. Mature blood cells lack a nucleus, giving them a concave shape. They mainly contain a protein (hemoglobin) which transports oxygen and carbon dioxide

Hemoglobin needs iron to work correctly, which is why iron deficiency can cause anemia. Hemoglobin gives the blood its red colour.

Red Blood cells are the blood's most abundant cells, representing 45% of the blood volume. Matured blood cell lacks a nucleus, giving the cells a conical shape. They mainly contain a protein (hemoglobin) which transports oxygen and carbon dioxide

Hemoglobin needs iron to work correctly, which is why iron deficiency can cause anemia.

Hemoglobin gives the blood its red colour.

In the CBC, several parameters are used to evaluate red blood cells:

In the CBC, several parameters are used to evaluate red blood cells:

Redbloodcellcount

Hemoglobin (Hg): This is the amount of hemoglobin in your blood

Hematocrit (Hct): This is the percentage of your blood made up of red blood cells.

- Mean corpuscular volume (MCV): This is the average size of your red blood cells.

Mean corpuscular hemoglobin (MCH): This is the average quantity of hemoglobin in each red blood cell.

Red cell distribution width (RDW): This is the degree of difference in red blood cell size: if the red blood cells are closer to the same size, the RDW will be below.

WhiteBloodCells:

White blood cells are part of the immune system and help your body fight germs. They include several types of cells, all of which help protect you from diseases.

A typical CBC counts all types of white blood cells. However, physicians can also request a white blood cell differential analysis, which counts all white blood cells by type.

Neutrophils constitute 60-70% of the circulating white blood cells. They are the first responders when a pathogen is detected; they prevent infections by ingesting and releasing enzymes to destroy invading bacteria and fungi (2).

Neutrophils constitute 60- 70% of the circulating white blood cells. They are the first responders when a pathogen is detected; they prevent infections by ingesting and releasing enzymes to destroy invading bacteria and fungi (2).

Monocytes share neutrophils' " vacuum cleaner" function to fight infections, help remove damaged tissues, and destroy cancer cells. Still, they can also present pathogens to lymphocytes to stimulate the immune system's memory, which is essential to improving response over time.

Lymphocytes are much more common in the lymphatic system than in the blood. There are three subgroups of lymphocytes.

B cells make antibodies against pathogens to block invasion and facilitate their destruction

T cells destroy cells presenting pathogen molecules and coordinate the immune response.

Natural killer cells can destroy infected and cancerous cells that escape T cells.

Eosinophils compose about 2-4% of white blood cells in the circulating blood. They primarily deal with parasitic infections. They secrete chemicals that destroy large parasites, such as hookworms and tapeworms, that are too big for any white blood cell to ingest. Eosinophils are also the predominant inflammatory cells in allergic reactions (3).

Basophils, the rarest white blood cells (less than 0.5%), are chiefly responsible for allergic response by releasing histamine, which causes the dilation of blood vessels. They also secrete heparin, which inhibits blood clotting. Both substances promote the movement of other white blood cells into an area.

Platelets

Platelets are cell fragments that help your blood clot and control bleeding. They gather at the injured site, attach themselves to the blood vessel, and attract other platelets to connect to each other to plug the hole. They also initiate the coagulation process and facilitate wound healing.

Whatarethenormalvalues?

Abnormal values will fall below or above the reference ranges. The reference range varies depending on age, sex, and where you live. Each parameter of the CBC can indicate a possible issue that needs further investigation. In Table 1, you can see a few examples of potential causes.