Medical Matters > Blood Test: Platelet Count

ME Essential Autumn 2019


Has any link has been found regarding blood platelet abnormalities and ME/CFS? Over the past 3 years, my platelet levels have all been consistently higher than normal. On two occasions this has been due to infections. On other occasions, the inflammatory markers in my blood were normal – as was everything else. I’ve looked online for an explanation, but there are so many research papers I wasn’t sure where to start.


The simple answer to your question is that there is no anecdotal or research evidence to indicate that platelet abnormalities, including a raised level of platelets (doctors call this thrombocytosis), are involved in the pathogenesis (cause) of ME/CFS. Research from 2019 examined blood test results from people who had donated samples to the ME/CFS Biobank and it reported no significant difference in platelet levels between people with ME/CFS (including the severe cohort) and healthy controls – see below.

It should, however, be noted that a raised level of platelets can be associated with a number of conditions – some of which have ME/CFS-like symptoms. Examples include iron deficiency, inflammatory bowel disease and sarcoidosis. So, if this sort of abnormality persists, it does require further assessment, possibly involving input from a hospital haematologist (blood specialist).

In this analytical cross-sectional study, we aimed to explore potential haematological and biochemical markers for ME/CFS, and disease severity. We reviewed laboratory test results from 272 people with ME/CFS and 136 healthy controls participating in the UK ME/CFS Biobank (UKMEB).

After corrections for multiple comparisons, most results were within the normal range, but people with severe ME/CFS presented with lower median values of serum creatine kinase, compared to healthy controls and non-severe ME/CFS. The differences in CK concentrations persisted after adjusting for sex, age, body mass index, muscle mass, disease duration, and activity levels compared to controls.

This is the first report that serum CK concentrations are markedly reduced in severe ME/CFS, and these results suggest that serum CK merits further investigation as a biomarker for severe ME/CFS.

Nacul L et al. Evidence of Clinical Pathology Abnormalities in People with ME/CFS from an Analytic Cross-Sectional Study | April 2019

The NHS: Blood Tests

Full Blood Count (FBC)

This is a test to check the types and numbers of cells in your blood, including red blood cells, white blood cells and platelets. This can help give an indication of your general health, as well as provide important clues about certain health problems you may have. For example, an FBC may detect signs of:

    • iron deficiency anaemia or vitamin B12 deficiency anaemia.
    • infection or inflammation.
    • bleeding or clotting disorders.

Lab Tests Online

Platelet Count (also known as Thrombocyte count)

Platelets are small cell fragments and are found in the blood along with red cells and white cells. Platelets are produced in the bone marrow and released into the blood where they play an important role in coagulation (blood clotting), helping to stop bleeding when blood vessels are injured. They are the first cells to be recruited to sites of injury and, when activated, they clump together (aggregate), sealing the blood vessel and forming a blood clot. These small, disc-shaped cells usually live for around 5-10 days in the blood before they are destroyed.

Platelets are very important for efficient blood coagulation and preventing unnecessary or excessive blood loss. If there are too few platelets, or if the platelets that are present don’t function properly, then there may be problems with blood clot formation. On the other hand, too many platelets can increase the risk of blood clots that can block blood vessels and cause organ damage. The platelet count simply provides information on the number of these cells that are present in blood; it does not reveal if these cells are functioning properly. Specialised tests, called the platelet function tests, are used when there is suspicion of a platelet function defect.

A low platelet count may also be referred to as ‘thrombocytopenia’. Thrombocytopenia may be caused by either of two different processes that cause a reduction in the count; the bone marrow is not producing enough platelets, or the bone marrow is producing normal amounts but the platelets are being consumed (used) or destroyed faster than they should in the blood. Reduced platelet counts can be found in the following conditions, for example:

    • Immune thrombocytopenia –an immune condition that causes platelets to be destroyed faster than they should be due. This is one of the most common causes of thrombocytopenia, diagnosis involves ruling out any other potential cause of a low platelet count.
    • B12 or folate deficiency – severe deficiency of these B complex vitamins is associated with anaemia and, if severe, can also result in reduced platelet and white cell counts.
    • Infection and viruses – several infections and viruses can result in a reduced platelet count (e.g. parvovirus, cytomegalovirus, infectious mononucleosis)
    • Liver disease – established liver disease is associated with a low platelet count, among other changes to blood cells and proteins
    • Autoimmune disorders – such as lupus, can cause increased destruction of platelets…

A high platelet count, ‘thrombocytosis’, is due to overproduction of platelets by the bone marrow which can be caused by certain bone marrow disorders or might simply be a side-effect of another condition (reactive thrombocytosis). The platelet count may be increased as a reactive thrombocytosis in association with, for example:

    • Infection – in response to many infections,
    • Inflammation – chronic conditions such as Crohn’s disease, or other inflammatory processes.
    • Recent trauma – if there has been tissue damage, or after having an operation.
    • Poor spleen function – or in patients who have had their spleen removed.
    • Bleeding or recent blood loss – as a reactive process in response to bleeding.
    • Iron deficiency anaemia – especially where the anaemia is due to chronic blood loss (e.g. from a stomach ulcer).

More information and examples can be found by visiting Lab Tests Online.


Information provided by The ME Association should not be construed as medical advice. Don't assume any new or worsened symptoms are simply the result of having ME/CFS or Long Covid. We recommend that any information you deem relevant is discussed with your NHS GP as soon as possible. It is important that you seek personalised medical advice from the GP who is in charge of your care and who knows you well.

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