Norwich, Norfolk, UK: Scientists at the University of East Anglia have developed a blood test that can diagnose chronic fatigue syndrome (CFS), also known as ME, with 96 percent accuracy.
The researchers hope this breakthrough could pave the way for a similar test to diagnose long COVID, which shares overlapping symptoms with chronic fatigue syndrome.
Chronic Fatigue Syndrome is a debilitating condition characterized by extreme fatigue that is not relieved by rest. Around 400,000 people in the UK suffer from this syndrome, yet its cause and treatment remain controversial.
Many patients have been misdiagnosed or left undiagnosed for years, with some even being told that their illness is ‘all in their head.’

Professor Dmitry Pshezhetskiy, the lead researcher, said that, “With no definitive tests, many patients with chronic fatigue syndrome have gone undiagnosed or misdiagnosed for years. Our discovery offers the potential for a simple, accurate blood test to confirm a diagnosis, which could lead to earlier support and more effective management.”
The researchers used technology developed by biotech company Oxford BioDynamics to analyze DNA folding in blood samples from 47 patients with severe chronic fatigue syndrome symptoms and 61 healthy individuals.
Each cell contains around two meters of DNA, folded millions of times. These folds influence gene activation through epigenetic mechanisms, which are shaped by life events rather than DNA sequence alone.
The study found that patients with chronic fatigue syndrome exhibited a unique pattern of epigenetic markers. A test based on these patterns was able to identify 92 percent of patients with this syndrome and 98 percent of healthy participants, giving an overall accuracy of 96 percent.

Professor Pshezhetskiy noted that this marks a significant step forward in reliably diagnosing chronic fatigue syndrome and could transform its management.
Pshezhetskiy also highlighted the relevance to post-COVID syndrome (long COVID), which resembles chronic fatigue syndrome, noting that the research could help develop similar diagnostic tests for long COVID. However, experts caution that the test needs independent validation in larger clinical studies before it can be widely offered.
Professor Chris Ponting from the University of Edinburgh, who was not involved in the research, remarked that, “This test needs to be fully validated in better-designed and independent studies before clinical application. Even if validated, it will likely be expensive, around £1,000.”
The study has been published in the Journal of Translational Medicine, providing hope for patients suffering from chronic fatigue syndrome who have long awaited a definitive diagnostic tool.

