Medical Matters > Diagnosis: Blood Test

ME Essential Winter 2020


We keep hearing about different abnormalities that researchers are finding in the blood of people with ME and with brain scans. So why aren’t any of these tests, especially the new one from Professor Ron Davis’s group in America, being used by doctors to help confirm that someone has ME – or does not have ME?


As you are probably aware, there have been a large number of abnormalities involving brain, muscle, immune and endocrine systems, and metabolomics (the measurement of chemicals in the blood that are produced by cellular activities) reported in the ME/CFS research literature. These are often in small one-off studies and almost always in people with research-defined chronic fatigue syndrome (CFS) rather than M.E. as defined by the London M.E. criteria or other M.E. or even ME/CFS criteria.

For an abnormality to be elevated to the status of being a diagnostic biomarker, or test, it normally has to meet a number of basic requirements. This means that the abnormality has to be:

  • significant.
  • confirmed in several different research studies that are carried out in different research centres and published in reputable scientific journals.
  • present in everyone (or almost everyone) who has the condition.
  • absent in other similar conditions (to avoid producing what is called a false positive result).
  • linked to symptoms or disease activity.

As none of the current abnormalities involving biopsy, blood, autopsy, neuroimaging/brain scan, or anything else, currently meet these requirements we do not have a diagnostic test for M.E., CFS, or, ME/CFS.

The potential blood test that is being developed by the research group at Stanford, California has not been properly validated as a test for ME/CFS. So it is not available on the NHS, or to purchase here in the UK. And it is also not available to purchase in the USA.

There are a number of other possible diagnostic biomarkers being assessed – both here in the UK and abroad. The ME Association Ramsay Research Fund (RRF) is funding Dr Karl Morten and colleagues at Oxford to look at whether some of the metabolomic abnormalities could be used as diagnostic biomarkers. And if you check out all the research that is being carried out using blood samples from the UK ME/CFS Biobank (which is funded by the ME Association) there are a number of other researchers looking at possible biomarkers.

More information

  • The ME Association has produced a free summary of the 2021 NICE Clinical Guideline for ME/CFS. The guideline recommends a series of blood tests to be used to help exclude other possible causes for symptoms before a diagnosis of ME/CFS is made. We suggest that you familiarise yourselves with the guideline's recommendations and discuss those that are most relevant with your GP, ME/CFS Specialist Service, and/or social care service (as appropriate).
  • We also have detailed booklets that can be downloaded from the website shop:
    • We explain why an early and accurate diagnosis is so important. We examine the core symptoms, the need to take into account a patient's clinical history, the need for clinical investigations and blood tests, and consider other explanations for persistent symptoms.
    • There is no diagnostic blood test for ME/CFS – but testing your blood is essential to rule out other illnesses that can cause similar symptoms. We take an in-depth look at what blood tests should be taken to ensure your diagnosis is correct.


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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