Full Blood Count (FBC) Blood Test

Our FBC blood test (sometimes called a complete blood count) highlights abnormalities in your blood such as unexpectedly high or low numbers of blood cells. It gives you an overview of your general health and clues about certain health problems.

Conditions that can cause abnormal FBC results include anaemia, nutritional deficiencies (including iron, vitamin B12, and folate deficiency), inherited blood disorders, autoimmune disorders, infection, and bleeding and clotting disorders.

Red blood cells are vital for transporting oxygen around your body. Anything that affects their ability to do their job can lead to symptoms such as fatigue and weakness.

Our FBC test takes a detailed look at your red blood cells including their number, size, and volume. An abnormality in your red blood cells could indicate a medical problem such as anaemia.

White blood cells protect your body by fighting infection — they’re vital to supporting your body's immune system.

If your white blood cell count is high, this may be due to a recent or current infection, or inflammation in your body. Other possible causes include problems with the bone marrow or immune system, or a reaction to a medication.

A low white blood cell count may indicate a recent infection, an autoimmune disorder where your body mistakenly destroys white cells, a problem with white blood cell production, and in rare cases, it could be a sign of cancer.

Blood has four main components. The main component is plasma (60%) — a liquid made up of water, fat, protein, sugar, and salts. Blood cells make up the remaining 40% and include:

-Red blood cells — containing haemoglobin, which transports oxygen around the body

-White blood cells — the cells of the immune system that fight infection

-Platelets — cells that help to clot the blood to stop bleeding

Anaemia can have many different causes. Low iron (iron deficiency) is the most common nutritional cause, but it can also be caused by folate and vitamin B12 deficiency. Other causes of anaemia include blood loss, inherited red blood cell disorders, and chronic conditions such as kidney disease.

Treatment for anaemia will be based on the underlying cause, and many causes of anaemia are unrelated to diet or lifestyle. However, iron deficiency anaemia is one type of anaemia that may be improved by adding more iron-rich foods to your diet. Good sources of iron include red meat, poultry, fish, and shellfish. Plant-based sources include lentils, beans, tofu, and dark green, leafy vegetables.

A full blood count test may provide clues to liver function problems, such as a decrease in red blood cells and clotting issues, but further investigations would be needed to make a diagnosis.

Our Liver Function Blood Test covers a range of key markers of liver health including serum albumin. A low level of serum albumin or raised transaminases can suggest your liver isn’t working properly.

A full blood count test is not used to check for diabetes. If you think you’re at risk of developing diabetes, you can test your blood sugar levels with our at-home finger-prick Diabetes (HbA1c) Blood Test — this assesses your blood sugar control over the past 8–12 weeks.

Yes, you can take our FBC test at home by arranging a nurse visit. As this is a comprehensive test, your blood sample will need to be taken from a vein in your arm to ensure that the sample is sufficient.

Alternatively, you can visit one of our partner clinics to have your blood sample taken at a time that suits you.