ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

81–100 of 525 studies

E2 ModerateCohortPEM unclearCase-Control

Phosphoproteomic analysis reveals differential associations between liver-spleen disharmony and qi-blood deficiency syndromes in chronic fatigue syndrome.

Zhang, Jiabao, Tian, Ying, Sun, Guanghan et al.·Journal of translational medicine·2026

Researchers compared blood protein markers in 30 people—10 with ME/CFS showing Traditional Chinese Medicine (TCM) 'Liver-Spleen Disharmony' patterns, 10 with 'Qi-Blood Deficiency' patterns, and 10 healthy controls—using advanced protein analysis. They observed different patterns of phosphorylated proteins (chemical modifications on proteins) between the two ME/CFS groups and healthy controls, suggesting that TCM pattern categories may have distinct molecular signatures. However, this is an early exploratory study with a small sample size, and these findings have not yet been replicated.

BiomarkersDiagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

Factors Associated with Fibromyalgia Diagnosis amongst People Meeting Criteria: Results from UK Biobank.

Kim, Sung-A, Macfarlane, Gary J, Beasley, Marcus J·Arthritis care & research·2026

This study examined UK Biobank data to understand why many people who meet the clinical criteria for fibromyalgia do not receive a formal diagnosis from a doctor. Researchers found that about 73% of individuals meeting fibromyalgia criteria had not been diagnosed, and identified several factors associated with not receiving a diagnosis—including being male, being older, having shorter pain duration, and reporting less frequent fatigue. The findings suggest that diagnostic bias and stereotypical perceptions of fibromyalgia may delay or prevent people from getting a diagnosis, though this is one cross-sectional study and does not establish why these patterns occur.

Pain and SensitizationDiagnostics

E2 ModerateCohortPEM unclearCase-Control

Microvascular remodeling and endothelial dysfunction across the post-COVID-19 spectrum: a prospective observational case-control study.

Wallraven, Timon, Günthner, Roman, Lethen, Isabelle et al.·BMC medicine·2026

Researchers studied blood vessel changes in the tiny vessels of the eye (using a technique called retinal vessel analysis) in people with post-COVID-19 syndrome and a subgroup meeting ME/CFS criteria, compared to people who recovered from COVID-19 and those never infected. People with post-COVID-19 syndrome, particularly those meeting ME/CFS criteria, showed narrower arteries and altered vessel patterns associated with worse symptoms and higher inflammation markers. While these findings are reported as preliminary observations, the relevance of post-COVID-19 vessel changes to ME/CFS specifically remains unclear, and this study does not yet establish whether such changes cause symptoms or could guide treatment.

BiomarkersDiagnosticsLong COVID Overlap

E2 ModerateDiagnosticPEM unclearCross-Sectional

Improving myalgic encephalomyelitis population sampling: Applying an online respondent-driven method to address biases in G93.3 register data.

Kielland, Anne, Liu, Jing, Tyldum, Guri et al.·Journal of health psychology·2026

This study looked at how well official medical records capture ME/CFS cases and who gets diagnosed. Researchers found that medical register data misses many cases and disproportionately underrepresents people from lower-income backgrounds. They used a new online method to find ME/CFS patients more accurately and checked whether official diagnoses matched recognized diagnostic criteria.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients.

Tomaskovic, Aleksandar, Weber, Vincent, Ochmann, David T et al.·Sports medicine - open·2026

A cross-sectional study of 92 severely ill post-COVID patients found that those meeting ME/CFS criteria had lower measured aerobic capacity (oxygen uptake and power output) on exercise testing compared to post-COVID patients without ME/CFS. Two-thirds of all patients showed objective signs of work disability on testing, and these measurements correlated with patients' own reports of disability and their employment status. The relevance of these findings specifically to ME/CFS requires caution, as the study enrolled primarily post-COVID patients, and the overlap between these conditions remains incompletely understood.

Severe MEDiagnosticsLong COVID OverlapPost-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

The Diagnostic Journey of Dysautonomia Patients: Insights from a Patient-Reported Outcome Study.

O'Dell, John A, Walker, Ash, Latham, Andrew J et al.·Journal of patient experience·2025

This study followed 672 adults with dysautonomia (a condition where the nervous system that controls automatic body functions doesn't work properly) to understand how long it takes to get diagnosed and which doctors help with diagnosis. On average, it took 7.7 years for people to receive a diagnosis, and they often saw multiple types of doctors before getting answers. The study found that dysautonomia commonly occurs alongside other conditions like Ehlers-Danlos syndrome, mast cell disorders, and ME/CFS, which can make diagnosis even more confusing.

Autonomic Nervous SystemDiagnostics

E2 ModeratePEM unclearBiobank-Resource

Defining a High-Quality Myalgic Encephalomyelitis/Chronic Fatigue Syndrome cohort in UK Biobank.

Samms, Gemma L, Ponting, Chris P·NIHR open research·2025

This study looked at how ME/CFS is identified in UK Biobank, a large database of health information from hundreds of thousands of people. Researchers found that about 1 in 100 UK Biobank participants had some evidence of ME/CFS, but only about one-third had strong, consistent evidence across multiple records. When they accounted for people too ill to participate in the study, they estimated that around 410,000 people in the UK have ME/CFS.

Diagnostics

E2 ModerateCohortPEM unclearRegistry-Resource

Unequal access to diagnosis of myalgic encephalomyelitis in England.

Samms, Gemma Louise, Ponting, Chris P·BMC public health·2025

This study examined NHS records from England to understand how many people have ME/CFS and whether diagnosis is fair across different groups. Researchers found that about 100,000 people in England have been officially diagnosed with ME/CFS, but the actual number may be much higher—around 404,000 in the UK. The diagnosis rates varied significantly depending on gender, age, ethnicity, and where people live, suggesting some patients are being missed.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Quantifying the Degree of Fatigue in People Reporting Symptoms of Post-COVID-19 Syndrome: Results from a Rasch Analysis.

Mayo, Nancy, Brouillette, Marie-Josée, Fellows, Lesley K et al.·Physiotherapy Canada. Physiotherapie Canada·2025

Researchers in this study developed and tested a new questionnaire to measure fatigue severity in people with post-COVID-19 syndrome. The measure, called the PCS Fatigue Severity Measure V1, performed well in their analysis of 414 participants—it correlated strongly with other fatigue measures and distinguished between people still working and those on sick leave. However, this is early-stage research in a single Canadian cohort, and the authors note that further testing in other populations is needed to confirm the measure's reliability over time.

DiagnosticsPost-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Chronicity rhetoric in health and welfare systems inhibits patient recovery: a qualitative, ethnographic study of fibromyalgia care.

Cupit, Caroline, Finlay, Teresa, Pope, Catherine et al.·Social science & medicine (1982)·2025

This study looked at how healthcare and welfare systems talk about fibromyalgia and similar long-term conditions like ME/CFS. Researchers found that when doctors and officials constantly describe these conditions as permanent and unchangeable ('chronicity rhetoric'), it can actually get in the way of patients healing and recovering. The study suggests that changing how we talk about these conditions—and how our support systems are designed—might help patients feel more hopeful and do better.

Diagnostics

E2 ModerateCohortPEM unclearObservational

Assessing the influence of lived-experience experts on healthcare providers in a virtual community of practice: a qualitative study.

Weaver, Stephanie Sargent, Carry, Monique, Bertolli, Jeanne et al.·Frontiers in health services·2025

This study looked at whether having patients with lived experience of Long COVID and ME/CFS help teach doctors made a real difference in patient care. Researchers tracked what these patient-experts recommended to doctors through online training sessions from 2022-2024, and then asked actual patients if their doctors seemed to apply that advice. The main recommendations focused on validating patients' experiences, showing empathy, helping with referrals, and supporting self-care. Patients reported noticing positive changes in how their doctors treated them, suggesting that including patient-experts in medical education actually works.

Diagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

Validity and diagnostic overlap of functional somatic syndrome diagnoses.

van der Meulen, Monica L, Bos, Martje, Bakker, Stephan J L et al.·Journal of psychosomatic research·2024

This study looked at how often three common conditions—ME/CFS, fibromyalgia, and irritable bowel syndrome—occur together in the general population. Researchers surveyed nearly 90,000 people and found that these conditions overlap far more often than would happen by pure chance, especially when they last longer and cause more serious symptoms. This suggests these conditions may share common underlying features.

Diagnostics

E2 ModerateCohortPEM requiredCross-Sectional

Illness presentation and quality of life in myalgic encephalomyelitis/chronic fatigue syndrome and post COVID-19 condition: a pilot Australian cross-sectional study.

Weigel, Breanna, Eaton-Fitch, Natalie, Thapaliya, Kiran et al.·Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation·2024

This study compared symptoms and quality of life in people with ME/CFS, people with long COVID, and healthy controls in Australia. Both ME/CFS and long COVID patients experienced similar debilitating symptoms affecting memory, sleep, and physical function, and both groups had much lower quality of life scores than healthy people. The findings suggest that ME/CFS and long COVID are similarly serious illnesses that require comprehensive medical care.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Frequency and characteristics of chronic fatigue syndrome in multiple sclerosis patients at a university hospital in Eastern Saudi Arabia.

AlAmri, Abdullah S, AlShamrani, Foziah J, AlMohish, Noor M et al.·Journal of family & community medicine·2024

This study looked at fatigue in 225 people with multiple sclerosis (MS) to see how many also had chronic fatigue syndrome (CFS). About half of the MS patients experienced long-lasting fatigue lasting over 6 months. Researchers found that 7% of patients truly met the medical criteria for CFS, while 17% believed they had CFS but didn't meet the official diagnostic standards, suggesting confusion about what CFS actually is.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

[What Medical Specialties do ME/CFS Sufferers Consult? A Public Health Study on the need for Better Medical Education and Training].

Habermann-Horstmeier, Lotte, Horstmeier, Lukas Maximilian·Gesundheitswesen (Bundesverband der Arzte des Offentlichen Gesundheitsdienstes (Germany))·2024

This German study surveyed 674 ME/CFS patients to understand how they navigate the healthcare system and how long diagnosis takes. Patients saw an average of 6-15 different doctors from various specialties before getting diagnosed, with the diagnostic journey taking up to 10 years for most people. The study found that doctors often refer patients around based on individual symptoms rather than recognizing ME/CFS as a whole condition, highlighting the urgent need for better training about ME/CFS across all medical fields.

Diagnostics

E2 ModerateCohortPEM requiredLongitudinal

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After SARS-CoV-2 Infection.

Unger, Elizabeth R, Lin, Jin-Mann S, Wisk, Lauren E et al.·JAMA network open·2024

This study followed over 4,300 people for up to 12 months to see whether COVID-19 infection caused ME/CFS-like symptoms. Researchers found that about 3-4% of people reported ME/CFS-like symptoms after their acute illness, but this rate was similar whether they had tested positive or negative for COVID-19. The results suggest that while some people do develop long-lasting symptoms after illness, COVID-19 may not be uniquely causing ME/CFS more often than other infections.

DiagnosticsLong COVID Overlap

E2 ModerateBehavioralPEM not requiredCross-Sectional

Factors associated with having previously received a diagnosis of fibromyalgia, chronic fatigue syndrome and irritable bowel syndrome: A cross sectional DanFunD study.

Tattan, Mais, Ørnbøl, Eva, Wellnitz, Kaare Bro et al.·Journal of psychosomatic research·2024

This study looked at 1,704 people with symptoms of functional somatic disorders (including ME/CFS, fibromyalgia, and irritable bowel syndrome) to understand who had received a diagnosis from a doctor. The researchers found that people—especially women—who had poor quality of life and negative beliefs about their illness were more likely to have received an official diagnosis. The study suggests that factors beyond just having symptoms affect whether people get diagnosed with these conditions.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

[Systems thinking, subjective findings and diagnostic "pigeonholing" in ME/CFS: A mainly qualitative public health study from a patient perspective].

Habermann-Horstmeier, Lotte, Horstmeier, Lukas Maximilian·Deutsche medizinische Wochenschrift (1946)·2024

This German study asked 544 ME/CFS patients about their experiences getting diagnosed and working with doctors. Patients reported that many doctors don't recognize ME/CFS as a real disease, instead dismissing it as purely psychological. The study found that poor diagnosis experiences and lack of doctor recognition of ME/CFS as a biological multisystem illness significantly damage the relationship between patients and their healthcare providers.

Diagnostics

E2 ModeratePEM unclearRegistry-Resource

The German Multicenter Registry for ME/CFS (MECFS-R).

Hieber, Hannah, Pricoco, Rafael, Gerrer, Katrin et al.·Journal of clinical medicine·2024

German researchers created a registry to collect detailed health information from ME/CFS patients across multiple medical centers. In their first group of 174 patients, they found that most had a viral illness before developing ME/CFS, with nearly half triggered by COVID-19. Patients reported severe fatigue and greatly reduced quality of life, with significant limitations in daily activities.

Diagnostics

E2 ModerateCohortPEM unclearCross-Sectional

Classification Accuracy and Description of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in an Integrated Health Care System, 2006-2017.

Liles, Elizabeth G, Irving, Stephanie A, Koppolu, Padma et al.·The Permanente journal·2024

This study looked at how often ME/CFS is diagnosed in a large health care system by checking electronic medical records from 2006 to 2017. Researchers found that while doctors used ME/CFS diagnosis codes for over 500 patients, only about 34% of the cases they reviewed actually matched the real diagnostic criteria for ME/CFS. This shows that relying only on diagnosis codes in medical records can give an inaccurate picture of how many people truly have ME/CFS.

Diagnostics

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Phosphoproteomic analysis reveals differential associations between liver-spleen disharmony and qi-blood deficiency syndromes in chronic fatigue syndrome.

Factors Associated with Fibromyalgia Diagnosis amongst People Meeting Criteria: Results from UK Biobank.

Microvascular remodeling and endothelial dysfunction across the post-COVID-19 spectrum: a prospective observational case-control study.

Improving myalgic encephalomyelitis population sampling: Applying an online respondent-driven method to address biases in G93.3 register data.

Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients.

The Diagnostic Journey of Dysautonomia Patients: Insights from a Patient-Reported Outcome Study.

Defining a High-Quality Myalgic Encephalomyelitis/Chronic Fatigue Syndrome cohort in UK Biobank.

Unequal access to diagnosis of myalgic encephalomyelitis in England.

Quantifying the Degree of Fatigue in People Reporting Symptoms of Post-COVID-19 Syndrome: Results from a Rasch Analysis.

Chronicity rhetoric in health and welfare systems inhibits patient recovery: a qualitative, ethnographic study of fibromyalgia care.

Assessing the influence of lived-experience experts on healthcare providers in a virtual community of practice: a qualitative study.

Validity and diagnostic overlap of functional somatic syndrome diagnoses.

Illness presentation and quality of life in myalgic encephalomyelitis/chronic fatigue syndrome and post COVID-19 condition: a pilot Australian cross-sectional study.

Frequency and characteristics of chronic fatigue syndrome in multiple sclerosis patients at a university hospital in Eastern Saudi Arabia.

[What Medical Specialties do ME/CFS Sufferers Consult? A Public Health Study on the need for Better Medical Education and Training].

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After SARS-CoV-2 Infection.

Factors associated with having previously received a diagnosis of fibromyalgia, chronic fatigue syndrome and irritable bowel syndrome: A cross sectional DanFunD study.

[Systems thinking, subjective findings and diagnostic "pigeonholing" in ME/CFS: A mainly qualitative public health study from a patient perspective].

The German Multicenter Registry for ME/CFS (MECFS-R).

Classification Accuracy and Description of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in an Integrated Health Care System, 2006-2017.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research