Full Blood Count (FBC) Blood Test, from our experts to you.
Dr Sam Rodgers MBBS, MRCGP

Chief Medical Officer

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What is
an FBC?

Our Full Blood Count (FBC) blood test, also known as a Complete Blood Count (CBC) or Haematology profile, is routinely used by doctors to examine the health of your red, white, and clotting blood cells.


Why check my
red blood cells?

Red cells are vital for transporting oxygen around the body, and anything that affects their ability to do so can lead to symptoms, including fatigue. An FBC looks at the size, shape, and volume of your red blood cells and will help assess whether you are suffering from anaemia, either caused by a deficiency in iron or vitamin B12.


What can I learn
from my white blood cells?

White blood cells are key to supporting your body's immune system and can indicate whether you are suffering from or have recently suffered from an injury or infection.


What's Included?

Clotting status
Red blood cells
White blood cells
Select profile for more information

Platelet count Platelets or clotting cells are the smallest type of blood cell. They are formed in the bone marrow and are important in blood clotting. When bleeding occurs, the platelets swell, clump together and form a sticky plug (a clot) which helps stop the bleeding.
MPV MPV, or Mean Platelet Volume, is a measurement of the average size of your platelets. Platelets are fragmented cells within the blood that aid the process of clot formation. MPV provides an indication of platelet production in your bone marrow.
Haemoglobin Haemoglobin is a protein in red blood cells which carries oxygen around the body and gives the blood its red colour. This test measures the amount of haemoglobin in the blood and is a good measure of the blood's ability to carry oxygen around the body.
Haematocrit HCT (haematocrit) measures the amount of space (volume) within the blood that is taken up by red blood cells.
Red cell count Red Blood Cell (RBC) Count analyses the number of red blood cells in the blood. Red blood cells carry oxygen from the lungs to the rest of the body, where it can be used to fuel energy processes such as movement and respiration. They also carry carbon dioxide produced from cells back to the lungs so that it can be exhaled.
MCV MCV (mean corpuscular volume) reflects the average size of your red blood cells. This is important to measure, as it can indicate how much oxygen your cells are likely to be transporting around the body.
MCH MCH (mean corpuscular haemoglobin) measures the average amount of haemoglobin contained in one of your red blood cells.
MCHC MCHC (mean corpuscular haemoglobin concentration) is the average concentration of haemoglobin in your red blood cells. Haemoglobin is a molecule which allows red blood cells to transport oxygen around the body.
RDW Red blood cell distribution width (RDW) indicates whether your red blood cells are all the same size, or different sizes or shapes. Normally cells are fairly uniform both in size and in shape, but some blood disorders may cause your red blood cells to form in abnormal sizes. This test measures the difference between the largest and the smallest red blood cell.
White cell count White Blood Cell (WBC) Count measures the number of white blood cells in the blood. White blood cells are key to your body's immune system. They fight infections and protect your body from foreign invaders such as harmful germs and bacteria. Additionally, they produce many antibodies and memory cells to protect you from further infections with the same germ.
Neutrophils Neutrophils are the most abundant type of white blood cell in the body and are responsible for helping your body fight infection. When a germ is initially detected by the body, neutrophils are the defence system which go out and attack the germ before any of your other white blood cells. When neutrophils are low you can be more vulnerable to illness and infection.
Lymphocytes Lymphocytes are a type of white blood cell which fight bacterial and viral infections. They are the subset of white blood cells involved in the more specific response to infections, which can identify and differentiate between different foreign organisms that enter the body. As well as fighting infection, they produce antibodies and memory cells to help to prevent future infections from the same germ. Lymphocytes include T cells, B cells and natural killer cells.
Monocytes Monocytes are a type of white blood cell that surround and destroy germs and dead or damaged cells from the blood. The heat and swelling that you feel when a body part is inflamed, for example after a cut on your finger, is caused by the activities of these cells.
Eosinophils Eosinophils are a type of white blood cell that are responsible for removing parasitic infections and regulating inflammation to mark an infected site. They also play a role in allergy and in asthma.
Basophils Basophils are a type of white blood cell that protect your body from bacteria and parasites such as ticks. They also play a role in allergic reactions.

Frequently asked questions

What is a Full Blood Count Blood Test?

A Full Blood Count Blood Test, or a haematology profile, is a routine test to check your general health and immune function. Generally, it is for people who have a history of blood disorders, are experiencing symptoms of low iron or would like to check their white blood cell count for, or after, an infection or inflammation.

What does a Full Blood Count Blood Test look for?

By examining the components of blood, including red and white blood cells and platelets, a FBC tests for abnormalities in your blood. This can indicate infection or inflammation in the body and check for anaemia, which can either be caused by iron or vitamin B12 deficiency.

Can a Full Blood Count Blood Test detect diabetes?

A full blood count test is not used to detect diabetes. The two types of blood tests used to detect diabetes are the fasting plasma glucose (FPG) test, which measures blood sugar after you’ve fasted for 8 hours, and the HbA1C blood test, which identifies blood sugar levels over the previous 8-10 weeks.

If you believe you are at risk of developing diabetes, you can test your blood sugar levels with our simple finger-prick, Diabetes (HbA1C) Blood Test.

How long does a Full Blood Count Blood Test take?

Blood test results can take anything from a few hours to a few weeks to be processed, depending on whether you go through the NHS, a private specialist or a digital consumer health company. Our full guide to blood testing explains exactly how blood testing works.