ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

2781 studies

141–160 of 2,781 studies

E2 ModerateCohortPEM requiredCross-Sectional

Exploration of Intersections and Divergences of Long COVID and Chronic Fatigue Syndrome.

Kouyoumdjian, Joao A, Yamamoto, Leticia A, Graca, Carla R·Cureus·2025

This study looked at how Long COVID and ME/CFS might be related by comparing people with Long COVID symptoms to those without and healthy controls. While many Long COVID patients experienced symptoms that overlap with ME/CFS—like post-exertional malaise (feeling worse after activity), brain fog, and sleep problems—only about 1 in 5 Long COVID patients actually met the official diagnostic criteria for ME/CFS. The findings suggest that Long COVID and ME/CFS are related but distinct conditions.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearLongitudinal

Health outcomes up to 3 years and post-exertional malaise in patients after hospitalization for COVID-19: a multicentre prospective cohort study (CO-FLOW).

Berentschot, Julia C, Bek, L Martine, Drost, Manon et al.·The Lancet regional health. Europe·2025

This study followed 299 people hospitalized with COVID-19 for three years after discharge to track their recovery. While some improved over time, many people continued experiencing fatigue, memory problems, and cognitive difficulties—and these problems actually got worse between years 2 and 3. About one-third of patients developed post-exertional malaise (PEM), a condition where activity makes symptoms significantly worse, and these patients had more severe and persistent health problems throughout the study.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearLongitudinal

Long-COVID in children and their parents: A prospective cohort study.

Iijima, Hiroyuki, Funaki, Takanori, Kubota, Mitsuru·Pediatrics international : official journal of the Japan Pediatric Society·2025

This study followed Japanese children hospitalized with COVID-19 and their parents to see how many developed long-COVID symptoms. About 45% of children had lingering symptoms one month after infection, dropping to 23% by six months. The most common symptoms were cough, tiredness, and sleep problems, with sleep issues being most strongly linked to a reduced quality of life.

Sleep

E2 ModerateCohortPEM not requiredCross-Sectional

Association between pre-existing chronic conditions and severity of first SARS-CoV-2 infection symptoms among adults living in Canada: a population-based survey analysis from January 2020 to August 2022.

Cheta, Nicholas, Zakaria, Dianne, Demers, Alain et al.·BMC public health·2025

This Canadian study looked at whether people with long-term health conditions experienced more severe COVID-19 symptoms when they caught the virus. Researchers surveyed over 10,000 adults from 2020 to 2022 and found that certain conditions—like chronic lung disease, high blood pressure, ME/CFS, fibromyalgia, and arthritis—were linked to worse COVID-19 symptoms. This information can help doctors identify who might need extra support or preventive care when facing a COVID-19 infection.

E2 ModerateCohortPEM not requiredCross-Sectional

Deep learning analysis of long COVID and vaccine impact in low- and middle-income countries (LMICs): development of a risk calculator in a multicentric study.

Shaheen, Ahmed, Shaheen, Nour, Long COVID Collaboration Study Group in the LMICs et al.·Frontiers in public health·2025

Researchers studied over 2,400 COVID-19 patients in low- and middle-income countries to understand why some people develop long-lasting symptoms like chronic fatigue and depression after infection. They used advanced computer analysis to identify which patients were at highest risk for these prolonged symptoms. The study found that vaccination reduced the risk of developing these long-term problems, and that older age, being female, and smoking were linked to higher risk of chronic fatigue.

E2 ModerateCohortPEM unclearCross-Sectional

Autonomic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Findings from the Multi-Site Clinical Assessment of ME/CFS (MCAM) Study in the USA.

Issa, Anindita, Lin, Jin-Mann S, Chen, Yang et al.·Journal of clinical medicine·2025

This study found that people with ME/CFS experience much higher levels of autonomic nervous system problems—which control things like heart rate, blood pressure, and digestion—compared to healthy people. Nearly all ME/CFS patients (97%) had at least one autonomic symptom, with common complaints including dizziness, cold hands and feet, and difficulty standing up. The more autonomic symptoms someone had, especially in certain areas like blood pressure regulation and stomach problems, the more severe their overall illness tended to be.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredCross-Sectional

The relationship between fatigue, sleep quality, and sleep deprivation.

Ayas, Fahriye Yonca, Özcebe, Lütfiye Hilal·Sleep & breathing = Schlaf & Atmung·2025

This study looked at how fatigue, sleep quality, and daytime sleepiness are connected in workplace employees. Researchers found that when people have poor sleep quality or don't sleep enough hours, they tend to experience more fatigue and daytime sleepiness—and these problems appear to affect each other in a cycle. The study suggests that addressing sleep problems may be important for reducing fatigue and improving workplace safety.

Sleep

E2 ModerateCohortPEM requiredCross-Sectional

Understanding symptom clusters, diagnosis and healthcare experiences in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID: a cross-sectional survey in the UK.

Mansoubi, Maedeh, Richards, Thomas, Ainsworth-Wells, Martine et al.·BMJ open·2025

This large UK survey asked over 8,800 people with ME/CFS or long COVID about their symptoms and experiences with healthcare. The study found that fatigue, brain fog, pain, and sleep problems are the most common symptoms, but people often wait years for a diagnosis. Even after new healthcare guidelines were introduced, most patients said they weren't satisfied with the care they received from the NHS.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Autonomic symptom burden, comorbidities and quality of life in women with Hypermobility Spectrum Disorders and hypermobile Ehlers-Danlos syndrome.

Collins Hutchinson, Meagan L, Liang, Emily, Fuster, Emily et al.·Autonomic neuroscience : basic & clinical·2025

This study looked at 84 women with connective tissue disorders (HSD/h-EDS) to understand how much autonomic nervous system problems they experience and how these affect their quality of life. The researchers found that these women had severe autonomic symptoms, with nearly 60% also having POTS and about 26% having ME/CFS. Overall, their quality of life was significantly worse than patients with other serious conditions like multiple sclerosis or rheumatoid arthritis.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredObservational

Age-Related Changes in the Clinical Picture of Long COVID.

Fain, Mindy J, Horne, Benjamin D, Horwitz, Leora I et al.·Journal of the American Geriatrics Society·2025

This study looked at how Long COVID symptoms change as people get older. Researchers compared people aged 18–39 with those aged 40–70+ who had recovered from COVID-19 infection at least 135 days earlier. They found that middle-aged adults (40–59) were more likely to have Long COVID than young adults, but surprisingly, adults aged 70+ were actually less likely to report it—and when they did, their symptoms looked different, with less fatigue, pain, and brain fog compared to younger people.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCase-Control

No reduced serum serotonin levels in patients with post-acute sequelae of COVID-19.

Mathé, Philipp, Götz, Veronika, Stete, Katarina et al.·Infection·2025

Researchers compared serotonin levels in the blood of 34 people with long COVID (PASC) and 14 healthy people. Serotonin is a chemical in the body that affects mood and fatigue. The study found no meaningful difference in serotonin levels between the two groups, suggesting that low serotonin is probably not the main cause of long COVID symptoms.

Biomarkers

E2 ModerateCohortPEM unclearCross-Sectional

Imbalanced Brain Neurochemicals in Long COVID and ME/CFS: A Preliminary Study Using MRI.

Thapaliya, Kiran, Marshall-Gradisnik, Sonya, Eaton-Fitch, Natalie et al.·The American journal of medicine·2025

Researchers used advanced brain imaging to measure chemical imbalances in ME/CFS and long COVID patients compared to healthy people. They found that two important brain chemicals—glutamate and N-acetyl-aspartate—were significantly higher in patients with both conditions. These chemical imbalances were connected to how severe patients' symptoms were, suggesting that abnormal brain chemistry may play a role in the exhaustion and other symptoms these patients experience.

Neuroinflammation

E2 ModerateDiagnosticPEM unclearCross-Sectional

Psychometric evaluation of the PROMIS® physical function short form 12a for use by adults with myalgic encephalomyelitis/chronic fatigue syndrome.

Yang, Manshu, Keller, San, Rafiee, Parisa et al.·Health and quality of life outcomes·2025

Researchers tested whether a questionnaire called PROMIS Physical Function Short Form (PF-SF) works well for measuring how much ME/CFS affects a person's ability to do physical activities. They asked 173 people with ME/CFS and 161 healthy people to complete the questionnaire and found that it accurately captured the differences in physical ability between the two groups. The questionnaire appears to be a reliable and useful tool for doctors and researchers to measure physical function in people with ME/CFS.

E2 ModerateCohortPEM unclearCross-Sectional

Physical activity and sedentariness levels in patients with post-exertional malaise resulting from post-COVID-19 syndrome.

Elkebir, Kamel-Eddine, Gilbert, Jo-Anne, Kugathasan, Thiffya Arabi et al.·Work (Reading, Mass.)·2025

This study looked at how physical activity changed in 154 people who developed post-exertional malaise (PEM)—extreme tiredness and pain that worsens after activity—following COVID-19. Researchers found that after COVID-19, these patients became much less active and spent more time sitting, especially at work. Women and those with more severe PEM were most affected by these changes.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

A Cross-Sectional Study of Symptom Prevalence, Frequency, Severity, and Impact of Long COVID in Scotland: Part I.

Mclaughlin, Marie, Cerexhe, Luke, Macdonald, Eilidh et al.·The American journal of medicine·2025

Researchers surveyed 253 people living with long COVID in Scotland to understand which symptoms are most common and how severe they are. The most frequent symptoms were post-exertional malaise (when activity makes symptoms worse), extreme tiredness, and thinking problems. The study found that people living in areas with more deprivation experienced more symptoms, but factors like vaccination status and age did not significantly affect symptom patterns.

Post-Exertional Malaise

E2 ModerateDiagnosticPEM unclearMethods-Paper

Reliability and validity of the German version of the DePaul Symptom Questionnaire Post-Exertional Malaise (DSQ-PEM).

Kuczyk, Charlotte, Nöhre, Mariel, Herrmann-Lingen, Christoph et al.·Frontiers in psychiatry·2025

Researchers tested a German-language questionnaire designed to measure post-exertional malaise (PEM)—the worsening of symptoms that happens after physical or mental activity in ME/CFS and long COVID. They found the questionnaire is reliable and accurately distinguishes between people with and without long COVID, making it a useful tool for German-speaking patients and doctors.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredLongitudinal

Temporal Dynamics of the Plasma Proteomic Landscape Reveals Maladaptation in ME/CFS Following Exertion.

Germain, Arnaud, Glass, Katherine A, Eckert, Melissa A et al.·Molecular & cellular proteomics : MCP·2025

Researchers studied what happens in the blood of ME/CFS patients during and after exercise to understand post-exertional malaise (PEM)—the worsening of symptoms that occurs after physical activity. They measured over 6,000 different proteins in 79 ME/CFS patients and 53 healthy controls before exercise, immediately after, and during recovery. They found that ME/CFS patients have abnormal protein changes during recovery that suggest their immune system and energy-producing cells are not working properly after exertion.

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study.

Thapaliya, Kiran, Marshall-Gradisnik, Sonya, Eaton-Fitch, Natalie et al.·PloS one·2025

Researchers used advanced brain imaging to compare a part of the brain called the hippocampus in long COVID patients, ME/CFS patients, and healthy people. They found that certain areas of the hippocampus were larger in both patient groups compared to healthy controls, and these size differences were linked to how severe symptoms like fatigue, pain, and memory problems were. This suggests that changes in brain structure might explain some of the cognitive difficulties these patients experience.

Cognitive Impairment

E2 ModerateCohortPEM requiredObservational

Efficacy of repeated immunoadsorption in patients with post-COVID myalgic encephalomyelitis/chronic fatigue syndrome and elevated β2-adrenergic receptor autoantibodies: a prospective cohort study.

Stein, Elisa, Heindrich, Cornelia, Wittke, Kirsten et al.·The Lancet regional health. Europe·2025

This study tested a blood-filtering treatment called immunoadsorption in 20 patients with post-COVID ME/CFS who had specific autoantibodies (immune proteins attacking their own bodies). After five treatment sessions, 70% of patients improved, with better physical function, reduced fatigue, and less post-exertional malaise lasting at least six months. The treatment removed harmful immune proteins from the blood and was generally well tolerated.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCase-Control

Diagnosis of chronic fatigue syndrome using beat-to-beat autonomic measurements.

Kujawski, Sławomir, Tabisz, Hanna, Morten, Karl J et al.·Journal of translational medicine·2025

Researchers used artificial intelligence to analyze how the heart and nervous system behave differently in ME/CFS patients compared to healthy people. By measuring heart rate changes beat-by-beat, they found a pattern that could identify ME/CFS patients with 89% accuracy. The key differences included a less responsive vagal nerve (which normally calms the body), a more active stress response in blood vessels, and less efficient heart pumping.

Autonomic Nervous System

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Evidence browser

Exploration of Intersections and Divergences of Long COVID and Chronic Fatigue Syndrome.

Health outcomes up to 3 years and post-exertional malaise in patients after hospitalization for COVID-19: a multicentre prospective cohort study (CO-FLOW).

Long-COVID in children and their parents: A prospective cohort study.

Association between pre-existing chronic conditions and severity of first SARS-CoV-2 infection symptoms among adults living in Canada: a population-based survey analysis from January 2020 to August 2022.

Deep learning analysis of long COVID and vaccine impact in low- and middle-income countries (LMICs): development of a risk calculator in a multicentric study.

Autonomic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Findings from the Multi-Site Clinical Assessment of ME/CFS (MCAM) Study in the USA.

The relationship between fatigue, sleep quality, and sleep deprivation.

Understanding symptom clusters, diagnosis and healthcare experiences in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID: a cross-sectional survey in the UK.

Autonomic symptom burden, comorbidities and quality of life in women with Hypermobility Spectrum Disorders and hypermobile Ehlers-Danlos syndrome.

Age-Related Changes in the Clinical Picture of Long COVID.

No reduced serum serotonin levels in patients with post-acute sequelae of COVID-19.

Imbalanced Brain Neurochemicals in Long COVID and ME/CFS: A Preliminary Study Using MRI.

Psychometric evaluation of the PROMIS® physical function short form 12a for use by adults with myalgic encephalomyelitis/chronic fatigue syndrome.

Physical activity and sedentariness levels in patients with post-exertional malaise resulting from post-COVID-19 syndrome.

A Cross-Sectional Study of Symptom Prevalence, Frequency, Severity, and Impact of Long COVID in Scotland: Part I.

Reliability and validity of the German version of the DePaul Symptom Questionnaire Post-Exertional Malaise (DSQ-PEM).

Temporal Dynamics of the Plasma Proteomic Landscape Reveals Maladaptation in ME/CFS Following Exertion.

Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study.

Efficacy of repeated immunoadsorption in patients with post-COVID myalgic encephalomyelitis/chronic fatigue syndrome and elevated β2-adrenergic receptor autoantibodies: a prospective cohort study.

Diagnosis of chronic fatigue syndrome using beat-to-beat autonomic measurements.

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