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  • Writer's pictureKim Atherton

Full Blood Count Explained

Updated: Dec 12, 2023

Have you received your Pathology Results? Did it include a Full Blood Count (FBC)? Would you like to have the results explained?

Full Blood Count (FBC)

The Full Blood Count (FBC), otherwise known as a Full Blood Examination (FBE), or Complete Blood Count (CBC), is a general screening test that helps identify many issues, should issues be present. The FBC looks at the various cells in our blood and provides analysis on them. The cells are generated in the bone marrow. When examined in the laboratory, they look like the images below. New cells are made in your Bone Marrow as shown below.

Picture of the inner bone marrow and then highlighting the blood cells that develop from it
Or blood cells stem from our Bone Marrow

Full Blood Count Results Explained

Test Marker

Description of Marker

Haemoglobin (Hb)

Haemoglobin is the 'iron containing' red protein whose job is to carry oxygen around our body.Haemoglobin is made up of Haem and Globin.


Red Blood Cells (RBC), otherwise known as erythrocytes, contain haemoglobin that carries oxygen to tissues. RCC = Red Cell Count. You need sufficient B12 and Folate to make RBC. RBC last approximately 120 days.

Haematocrit (Hct)

Haematocrit is the Packed Cell Volume (RBC + WBC). ​The amount of space that red blood cells take up in your blood.


Mean Cell Volume = the average size of our RBC's.


Mean Cell Haemoglobin is the amount of oxygen-carrying haemoglobin inside your red blood cells MCH=Hb/RCC


Mean Cell Haemoglobin Concentration is the total haemoglobin inside the red blood cells MCHC=Hb/Hct


Red Cell Distribution Width is the deviation in size between our Red Blood Cells. It is generally an early marker that may show an early indication of emerging issues.


There are 5 types. WCC = White Cell Count and is the sum of all the types. The numbers and types of white blood cells in your blood, including neutrophils, lymphocytes, monocytes, eosinophils and basophils. ​White Blood Cells are involved in our immune defence system.


Neutrophils are the most common type of circulating WBCs. They move to damaged or infected tissue in the body to engulf and destroy any bacteria.


Lymphocytes are found both in our blood and our lymphatic system. There are 3 types: B cells, T cells, and Natural Killer cells (NK), with specific jobs. Involved in viral infections.

Neutrophil: Lymphocyte Ratio

A ratio that can be calculated


Monocytes are similar to Neutrophils in that they migrate to a site of infection and engulf pathogens. They are involved in chronic inflammatory conditions.


Eosinophils respond to an allergic reaction, and may be present when there are parasites in our body. They control the extent of our immune responses.


Basophils are the least common and respond to allergic reactions.


Nucleated Red Blood Cells. RBC lose their nucleus when they circulate in blood. NRBC still have their nucleus.


These are essential for normal blood clotting. They help stop bleeding by joining together to create a temporary plug in broken blood vessels.

Platelet: Lymphocyte Ratio

A ratio that can be calculated


Erythrocyte Sedimentation Rate

Table: Components found within a Full Blood Count (FBC)

Nutrition is super important for us and we can see the results of poor nutrition in our blood test results, and our symptoms.

Our food choices, and the nutrients they provide are part of the essential building blocks to forming healthy cells.

For example, you need sufficient Iron, Vitamins B2, B5, B6, Biotin, and Minerals Zinc, Copper, Lipoid acid, Glycine to make Haemoglobin. Haem in the liver is the basis of our P450 enzymes involved in liver detoxification.

Conditions affecting Red Blood Cells

  • Thalassaemia, is a genetic condition resulting in the inability to make Haem molecules. Depending on the type and severity of Thalassaemia, patients may require blood transfusions. If someone is anaemic, the Mentzer Index (a ratio of MCV/RCC), can differentiate between Iron deficiency Anaemia (>13), or Thalassaemia (<13).

  • Anaemia is a condition in which the number of red blood cells or the haemoglobin concentration within them is lower than normal.

  • Polycythaemia is a condition characterised by an abnormal increase in red blood cells resulting in an elevation of haemoglobin or haematocrit.

Conditions affecting White Blood Cells
  • Infections - bacterial, viral

  • Allergies

  • Heavy Metal Toxicity

  • Obesity

  • Stress

  • Chronic Inflammation

  • Autoimmune Conditions

  • Sepsis

  • Medications

  • Nutritional deficiencies

  • Post virus effects

General advice for having blood tests taken:

Importantly, we need to be fasted, rested (no exercise prior), and hydrated (1 glass water), before we have a blood collection. Were these the conditions you had a blood collection in? Dehydration can impact on results: you may see an increase in RCC, Hct, Platelets, and Hb. Too much hydration, and recent exercise however, can temporarily cause a decrease in those same results. Pregnancy can also show a dilution effect in the 2nd trimester, which normalises itself in 3rd trimester.

If you would like to discuss your personal circumstances, or have your pathology results reviewed in line with your current situation, feel free to make a booking with me on the bookings tab on my website.

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