What does your Complete Blood Count (CBC) tell you?

Complete blood count

A complete blood count (CBC) is the customary or usual blood test your doctor may recommend. Your CBC report aids in

  1. Diagnosing certain blood cancers such as leukaemia and lymphoma
  2. Analyse if such cancers have spread to the bone marrow
  3. See how the human body responds to prominent cancer treatments
  4. Detecting other non-cancerous conditions

How do you define a Complete Blood Count (CBC)?

The CBC analysis involves the three major cellular components in your blood:

How is the CBC test carried out?

To conduct the CBC test, the lab technician extracts the blood sample from an individual, usually from the inside of the elbow. This is a quick and typically painless process.

On running the CBC, haematology analyzers determine whether the number of white blood cells, red blood cells and platelets is increasing or decreasing. The usual range of complete blood counts depends on age and gender. CBC helps diagnose various conditions such as anaemia, infections and cancer.

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What is inferred from the CBC results?

CBC tests infers the count of red blood cells (RBCs), white blood cells(WBCs) and platelets.

White blood cells in the blood that fight against foreign invaders such as viruses, bacteria and parasites. Some of the WBCs can also attack cancer cells. Platelets are those tiny cell fragments that circulate through the body and make blood clot normally.

White blood cell count or leukocyte count reveals the total number of white blood cells in a blood sample.

White blood cell differential count

A white blood cell differential test evaluates the number of white blood cell types. There are five major types of white blood cells with different roles in protecting the body. Your health care provider can learn valuable information about your health by measuring the levels of cells such as:

  • Neutrophils
  • Lymphocytes
  • Monocytes
  • Eosinophils
  • Basophils

Red blood cell count

Red blood cells circulate oxygen throughout your body. A red blood cell count (erythrocyte count) measures the number of red blood cells in a blood sample. The lab technicians measure red blood cells in different methods. The most common among them are:

  1. Hematocrit (Hct) – the percentage of your blood that comprises red blood cells
  2. Hemoglobin (Hgb) – the protein amount in red blood cells that carries oxygen

Platelet count

A platelet count reads the number of platelets in a sample of blood. Platelets are associated with the formation of blood clots during the bleeding.

Your health care team will provide the normal range of these counts on your CBC lab results.

Note that if the white blood cell count is high, it indicates the onset of an infection or inflammation. Moreover, it can also indicate problems with the bone marrow or immune system or a reaction to a specific medication. At the same time, low white blood cell count may reveal an autoimmune disorder destroying white blood cells or even cancer. Similarly, an abnormally high or low platelet count often indicates a medical condition, which may be due to side effects from medication.

CBC normal ranges listed below are for a healthy adult. Ranges vary based on the factors like sex, age and other conditions.

  • Hemoglobin, a protein that carries oxygen around the body, has a normal range of13.5 to 17.5 g/dL for men and 12 to 15.5 g/dL for women.
  • Hematocrit – normal range is a 0.33 to 0.42 ratio.
  • MCV (mean cell volume) – normal range is 74 to 87 fL.
  • MCH(mean corpuscular hemoglobin) – amount of hemoglobin per blood cell – normal range is 24 to 29 pg.
  • WBC – normal range is 4.5 to 12 x 109/L.

– neutrophils: 1.5 to 8 x 109/L

– lymphocytes: 1.4 to 5.7 x 109/L

– monocytes: 0.3 to 1 x 109/L

– eosinophils: 0 to 1 x 109/L

A normal platelet count reads between 150 and 475 x 109/L.

Key takeaways

A CBC test helps evaluate patients’ health. This test is also often done as a part of a routine medical check-up to help the doctor get a clear picture of the patient’s health.


The Information including but not limited to text, graphics, images and other material contained on this blog are intended for education and awareness only. No material on this blog is intended to be a substitute for professional medical help including diagnosis or treatment. It is always advisable to consult medical professional before relying on the content. Neither the Author nor Star Health and Allied Insurance Co. Ltd accepts any responsibility for any potential risk to any visitor/reader.

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