A full blood count looks at the numbers of different types of cells in the blood. For some cells it also looks at their size, shape or what is in them.
The blood is made up of 3 main parts, all with different jobs:
- Red blood cells carry oxygen around the body.
- White blood cells help to fight off infections and clear up damage.
- Platelets block holes in damaged blood vessels to stop bleeding.
These are in a liquid called plasma.
Someone might have a full blood count at the same time as a liver blood test or as part of a full liver screen
On this page:
Having the test
One sample of blood will be taken, usually from the arm. It should be fine to eat and drink as normal before the test.
More detail on what is tested:
Mean corpuscular volume (MCV)
This is a measure of the average size of the red blood cells. The MCV can sometimes be affected by problems with the liver.
Mean corpuscular haemoglobin (MCH)
This is a measure of the average amount of haemoglobin in the red blood cells.
White blood cells (WBC)
Also called: Leucocyte count
White blood cells are actually a group of different cells. They are all part of the immune system.
A high level of white blood cells can be caused by things like infections and blood disorders.
Lots of things can cause a decrease in the number of white blood cells. This includes some types of liver disease.
Neutrophils
Neutrophils are a type of white blood cell. They help to protect against bacterial infections. The number of neutrophils in the blood can vary a lot from day to day and between different people.
Lymphocytes
Also called: Lymphs
About 1 in 4 white blood cells are lymphocytes. They have a lot of different jobs in the immune system. They are sometimes divided into T-cells and B-cells.
Monocytes (% Mono)
Monocytes are large white blood cells. They can help to remove and clear up infections caused by things like bacteria.
Eosinophils (%EOS)
Eosinophils are white blood cells. They are usually involved in attacking parasites. The number of eosinophils in the blood can also be increased by conditions including hay fever, asthma and eczema.
Basophils (%Baso)
Basophils are a type of white blood cell. Some infections and inflammatory conditions can cause an increase in the number of basophils in the blood.
Platelets (Platelet count)
Platelets are small cells or parts of cells in the blood. They have an important role in stopping bleeding if you get a cut or bruise.
Many conditions, including some liver conditions can cause a low platelet count. You might also hear this called “thrombocytopaenia”.
You can find out more about thrombocytopaenia caused by cirrhosis here.
Mean platelet volume (MPV)
This looks at the size of platelets. Newer platelets are larger than older ones.
What do the results mean?
A full blood count looks at a lot of different things. It is important to get personal advice from the medical team about what your or your child’s results mean.
The results will be compared to a reference range. Sometimes called a “normal range”. You can find out more about reference ranges here.
You cannot get a diagnosis of liver disease just from a full blood count. But it can help doctors to decide on the next steps. It can also rule out other possible problems.
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This content was last reviewed: July 2025
Our expert reviewers:
We would like to thank everyone who helped with creating and reviewing this page. Including Professor Stephen Ryder, consultant hepatologist at Nottingham University Hospitals NHS trust and Dr Laura-Jane Armstrong, Associate GP, Avonside Health Centre. And all our patient reviewers.
Find out how we make our patient information.
Everyone’s experience of liver disease will be different. Always talk to your specialist medical team for personal advice.
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