Full Blood Count Test (Complete Blood Count)


£53.60 – Results in 4-6 Hours (Please note there is an additional from £89 consultation fee)

This is a very common blood test used by doctors to give an overall impression of patients’ health. FBC results can potentially flag up signs of a variety of diseases, such as anaemia, infection or bleeding/clotting disorders. See the section below for more uses for a Full Blood Count.

  • Full Blood Count
    • Haemoglobin
    • Haematocrit (HCT)
    • Red Cell Count
    • Mean Corpuscular Volume (MCV)
    • Mean Corpuscular Haemoglobin (MCH)
    • Mean Corpuscular Haemoglobin Concentration (MCHC)
    • Red Cell Distribution Width (RDW)
    • Platelet Count
    • Mean Platelet Volume (MPV)
    • White Cell Count:
      • Neutrophils
      • Lymphocytes
      • Monocytes
      • Eosinophils
      • Basophils



Blood Consists of 4 Major Components:

Click on each of the below components for more information as to why we measure such parameters.

All of these are measured during a Complete Blood Count blood test, as well as various sub-groups within each main group.

So what’s the point of measuring all of these different components?

The specific levels of each are very important in diagnosing a range of different diseases, as we’ll mention below.

The Full Blood Count blood test is potentially one of the simplest, yet most revealing medical blood tests available: there’s a lot that can be discovered from this one simple test.


Red Blood Cells

Anaemia is a common blood condition, defined as a decreased level of red blood cells or haemoglobin in the blood. It is regularly screened for by measuring haematocrit and haemoglobin levels – two main parameters of the Full Blood Count (FBC blood test).

Red blood cells carry and store oxygen in the blood. Low levels of red blood cells in the blood can be detrimental to your health, since essential organs and tissues may not be receiving adequate oxygen, necessary for essential energy-releasing chemical reactions.

There are a few different types of anaemia, the most common being Iron deficiency anaemia. This is when there is a lack of Iron in the body, usually due to insufficient dietary intake or poor absorption, which leads to a reduction in the number of red blood cells in your body.

Some symptoms of Iron deficiency anaemia include:

  • Lack of energy
  • Short on breath
  • Heart palpitations
  • Paleness

To detect and diagnose Iron deficiency anaemia, a doctor would measure both haematocrit and haemoglobin levels to confirm the anaemia. RBC size is also a useful indicator for iron deficiency anaemia, which is also measured via the Mean Corpuscular Volume (MCV) aspect of the full blood count.

Should Iron deficiency anaemia be implied from the FBC blood test results, a further test to measure Ferritin levels (the body’s iron store) would be useful to confirm the diagnosis.

Mean Corpuscular Volume is a determination of red blood cell health. A raised MCV level can be an indication of swollen red blood cells, often due to excess alcohol consumption.

Other common causes of anaemia include Vitamin B12 and Folate deficiencies, so blood tests for these will commonly be advised alongside a FBC blood test, if a patient complains of anaemia-like symptoms. If none of the above blood tests reveal the cause of the anaemia, further investigations may be recommended, such as a colonoscopy or endoscopy, to rule out internal bleeding, for example due to a stomach ulcer.

Usually, the cause of anaemia can be discovered from Full Blood Count, Vitamin B and Folate blood tests.


Platelets: Bleeding and Clotting Disorders

Blood clotting (otherwise known as coagulation) is a very important process, which helps stop excessive bleeding when a blood vessel is injured. Plasma proteins, such as fibrin, along with platelets work together to coagulate over the injury – preventing excess blood loss. By examining the plasma and platelets as part of a Full Blood Count blood test, this can give an insight into any potential bleeding or clotting conditions.


Clotting – hyper-coagulation

Blood clots, as explained above, are involved in the natural process to prevent excessive bleeding. However, if blood clots form too easily or don’t dissolve properly and travel through the body limiting or blocking blood flow.

A blood clot in a vein is called a thrombus (or venous thromboembolism), whereas a blood clot in other small vessels is called an embolism – both are considered dangerous medical conditions, and should urgent medical treatment should be sought.

Two common blood clotting conditions are deep vein thrombosis (DVT) and . While the deep vein thrombosis develops in the deep veins, usually in the leg, a pulmonary embolism is a blood clot in the pulmonary artery – the main blood vessel carrying blood from the heart to the lungs. Pulmonary embolisms are often the result of a blood clot from a DVT travelling up from the deep leg veins to the heart and lungs. It’s estimated that 10% of deep vein thromboses will develop into a pulmonary embolism.

Symptoms of deep vein thrombosis (DVT):

  • Swelling in one leg (often the lower leg/ calf)
  • Pain, that may worsen upon flexing the ankle
  • An ache in this area
  • Warm, red skin in this area

Symptoms of a pulmonary embolism (PE):

  • Chest pain – stabbing sensation, may be worse on inhalation
  • Shortness of breath – gradual or sudden
  • Dizziness, feeling faint, or even passing out
  • A dry cough, perhaps coughing up blood

There are a variety of risk factors for the development of blood clots, such as the following:

  • Being overweight or obese
  • A history of blood clots
  • Are over the age of 60
  • Receiving hormone replacement therapy treatment
  • Immobilisation of the legs:
    • Broken legs in plaster
    • Paralysis
    • Being bed-ridden, such as after surgery

If you’re at all concerned about blood clotting disorders, it’s a good idea to book in for a GP appointment at your earliest convenience at any London Clinic of our 18 locations. A Full Blood Count – FBC blood test will identify whether you have a healthy range of platelets, and other blood tests, such as Pre-travel DVT profiles are essential screening tools for anyone at risk of blood clots, especially prior to a period of immobilisation, such as long-haul flights.

However, if you’re clearly displaying the symptoms for DVT or PE, we’d recommend going straight to A&E for immediate ultrasound investigation and potential anticoagulant treatment.


Bleeding / Haemorrhaging

Conversely, platelet disorders can malfunction in the opposite sense to blood clotting: malfunctioning platelets, or low platelet levels can also lead to bleeding or haemorrhaging diseases. This means, clotting fails to happen properly, leading to slow clot formation and excessive bleeding.

Symptoms of bleeding disorders include

  • Unexplained and easy bruising
  • Heavy menstrual bleeding
  • Frequent nosebleeds
  • Excessive bleeding from small cuts
  • Any bleeding into joints

Thrombocytopenia is a condition whereby there is a deficiency of platelets in the blood, leading to the above mentioned symptoms: slow clotting after injury, as bleeding and easy bruising. This can be due to an autoimmune condition, such as lupus or rheumatoid arthritis, or may be for unknown reasons (idiopathic).

Other bleeding disorders include Von Willebrand disease and Haemophilia – both are inherited from parents. At London Doctors Clinic, our GP’s are able to request the blood tests for each, and provide any necessary specialist referrals to a haematologist, if required.

Bleeding or haemorrhaging conditions can be caused by a variety of factors, such as:

  • Low red blood cell count
  • Vitamin K deficiency
  • Side effect from certain medications

So again, if you’re concerned about bleeding disorders, booking in for a 15-minute GP consultation for Full Blood Count would be the first step in investigating the problem. From there, our GP’s can further scrutinise the issue with a variety of more complex blood tests, such as a coagulation blood profiles.


White Blood Cells: Infection

A Full Blood Count blood test is also a great indication of all kinds of infections. Elevated levels of white blood cell (WBCs), otherwise known as leucocytes, usually indicates some kind of infection.

A full blood count will usually measure levels of the following types of white blood cells:

  • Neutrophils
    • A type of phagocyte, involved in the ingestion of bacteria. Raised levels may suggest a bacterial infection is present.
  • Lymphocytes
    • If abnormally high, this can be a sign of either Hodgkins or non-Hodgkins lymphoma – a rare cancer of the lymphatic system.
  • Monocytes
    • Another important WBC involved in the process of phagocytosis –the engulfing of pathogens such as bacteria.
  • Eosinophils
    • Important inflammatory cells in involved in allergic reactions, such as hayfever. These WBCs also target mainly larger parasites than bacteria.
  • Basophils
    • Also involved in the inflammation process, as seen in allergies. Releases histamine as part of the immune system’s inflammatory response.


Overall, if any of our experienced GPs were to suspect any of the above mentioned diseases from your clinical history and symptoms, a Full Blood Count blood test would be a great start into diagnosis. From here, the doctor may recommend a variety of other blood tests, for more thorough investigation.


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  Same Day Full Blood Count Test Locations: Blackfriars, Canary Wharf, Holborn, Kings Cross, Liverpool Street, London Bridge, Oxford Street, Paddington, Victoria and Waterloo.