Evidence Atlas

The research, structured.

Every entry is classified by evidence level, disease context, and PEM status. Filter to find what matters for your situation.

135 studies

NewestEvidence
E0 ConsensusPEM ✗Moderate confidenceSystematic-ReviewReviewed

Burden of Disease in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Scoping Review.

Vester, Patricia, Boudouroglou-Walter, Stefanos, Schreyögg, Jonas et al.·Applied health economics and health policy·2026

This study looked at how much ME/CFS costs people and society, and how much it affects quality of life. Researchers found that ME/CFS causes significant health problems, lost work and school time, and costs thousands to hundreds of thousands of dollars per patient per year. The biggest costs come from lost income and productivity rather than direct medical care.

E3 PreliminaryPEM ✓Moderate confidenceEditorialMachine draft

Expert perspectives on Myalgic encephalomyelitis/chronic fatigue syndrome - Insights from the 3rd International Conference of the Charité Fatigue Center.

Fehrer, Annick, Windzio, Lara, Schoening, Simon et al.·Autoimmunity reviews·2026

Nearly 4,000 ME/CFS researchers and experts gathered at an international conference in May 2025 to share the latest discoveries about this serious illness. They discussed how ME/CFS develops, better ways to diagnose it, and new treatments being tested. The conference highlighted that while COVID-19 has brought more attention and funding to ME/CFS research, the disease is still not well understood and needs much more study.

Metabolic DysfunctionPost-Exertional MalaiseImmune Dysregulation
E0 ConsensusPEM ✓Moderate confidenceReview-NarrativeMachine draft

Myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia - overlap, differences, and emerging insights.

Murovska, Modra, Krumina, Angelika, Araja, Diana et al.·Journal of translational medicine·2026

ME/CFS and fibromyalgia are two different but often overlapping illnesses that cause severe fatigue, pain, and other debilitating symptoms. While they share many similarities, ME/CFS has a distinctive feature called post-exertional malaise—where activity makes symptoms dramatically worse for hours or days—while fibromyalgia does not. This review shows that the two conditions have different immune system patterns and may require different treatment approaches.

Cognitive ImpairmentPost-Exertional MalaiseImmune Dysregulation
E3 PreliminaryPEM ✗Weak / uncertainEditorialReviewed

An Overview of Severe Myalgic Encephalomyelitis.

Vink, Mark, Vink-Niese, Alexandra·Journal of clinical medicine·2026

This article reviews what we know about severe ME/CFS, a serious illness that can leave people completely bedbound and dependent on caregivers. Currently, there is no blood test or scan that can diagnose ME/CFS, though a special two-day exercise test can help document the problem. The authors emphasize that severe ME/CFS is a major medical condition that has received very little research funding, and there are currently no proven treatments available.

Post-Exertional Malaise
E3 PreliminaryPEM ?PreliminaryReview-NarrativeReviewed

Does Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Represent a Poly-Herpesvirus Post-Virus Infectious Disease?

Ariza, Maria Eugenia, Mena Palomo, Irene, Williams, Marshall V·Viruses·2025

This review examines whether ME/CFS might be caused by multiple herpes viruses working together, rather than a single virus. The researchers point out that many people develop ME/CFS after flu-like illnesses, suggesting viruses play a role, but scientists haven't found just one virus responsible. The study suggests that herpes viruses might cause ME/CFS through a special type of incomplete replication that hasn't been fully studied before.

E3 PreliminaryPEM ?PreliminaryEditorialReviewed

Post-infective myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-COVID as two puzzling faces of the same medal. Recent insights.

Chirumbolo, Salvatore, Franzini, Marianno, Tirelli, Umberto·International immunopharmacology·2025

This editorial examines the similarities between ME/CFS (a long-term illness causing extreme fatigue and other symptoms) and post-COVID syndrome (long-term effects some people experience after COVID-19 infection). The authors suggest these two conditions may share common underlying biological mechanisms, even though they arise from different infections. Understanding these connections could help doctors better recognize and treat both conditions.

E0 ConsensusPEM ✓Moderate confidenceReview-NarrativeReviewed

Gut Microbiome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Insights into Disease Mechanisms.

Nikolova, Ralitsa, Donchev, Deyan, Vaseva, Katya et al.·International journal of molecular sciences·2025

This review examines the connection between gut bacteria and ME/CFS, a condition characterized by exhaustion that worsens after activity. The authors explain how an imbalance in gut bacteria may damage the intestinal barrier, allowing bacterial particles to enter the bloodstream and trigger inflammation throughout the body. They also discuss how changes in gut bacteria might affect the brain, contributing to the brain fog and cognitive problems many ME/CFS patients experience.

Post-Exertional MalaiseImmune DysregulationGut Microbiome
E3 PreliminaryPEM ?PreliminaryReview-NarrativeReviewed

Autoantibody targeting therapies in post COVID syndrome and myalgic encephalomyelitis/chronic fatigue syndrome.

Wohlrab, Felix, Eltity, Mailam, Ufer, Friederike et al.·Expert opinion on biological therapy·2025

This article reviews how certain immune system proteins called autoantibodies—which the body mistakenly makes against itself—may contribute to both long COVID and ME/CFS. The authors discuss different treatment approaches that aim to reduce or neutralize these harmful autoantibodies. This editorial examines the current evidence and potential of these new therapies to help patients with these conditions.

Immune Dysregulation
E0 ConsensusPEM ?Moderate confidenceReview-NarrativeReviewed

Causes of symptoms and symptom persistence in long COVID and myalgic encephalomyelitis/chronic fatigue syndrome.

Komaroff, Anthony L, Dantzer, Robert·Cell reports. Medicine·2025

This review examines why long COVID and ME/CFS cause such severe, lasting symptoms. Researchers found that both conditions share similar biological problems, including immune system misbehavior, problems with blood vessel function, and issues with how cells produce energy. The study suggests that symptoms may come from both these biological problems and from ancient survival responses in the brain that were meant to protect us during serious illness.

NeuroinflammationGut Microbiome
E0 ConsensusPEM ?Moderate confidenceReview-NarrativeReviewed

Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Physical Fatigue Through the Perspective of Immunosenescence.

Luo, Yingzhe, Xu, Huimin, Xiong, Shaoquan et al.·Comprehensive Physiology·2025

This review examines how our immune system's aging process may explain the severe fatigue in ME/CFS. As immune cells age, they cause chronic inflammation that damages the energy-producing parts of our cells (mitochondria), while stress hormones and nerve signals become imbalanced. These problems across different body systems work together to create and maintain the exhaustion that defines ME/CFS.

E0 ConsensusPEM ✓Moderate confidenceReview-NarrativeReviewed

Towards an understanding of physical activity-induced post-exertional malaise: Insights into microvascular alterations and immunometabolic interactions in post-COVID condition and myalgic encephalomyelitis/chronic fatigue syndrome.

Haunhorst, Simon, Dudziak, Diana, Scheibenbogen, Carmen et al.·Infection·2025

This review examines why people with ME/CFS and long COVID feel much worse after physical activity—a condition called post-exertional malaise. The researchers found that when these patients exercise, their bodies struggle to use oxygen properly and produce energy efficiently, likely due to problems with tiny blood vessels and lingering immune activation. This causes a buildup of harmful substances like lactate and triggers further inflammation and exhaustion.

Post-Exertional Malaise
E2 ModeratePEM ✓PreliminaryObservationalReviewed

Post-exertional malaise in Long COVID: subjective reporting versus objective assessment.

Stussman, Barbara, Camarillo, Nathan, McCrossin, Gayle et al.·Frontiers in neurology·2025

This study looked at post-exertional malaise (PEM)—the symptom worsening that happens after activity—in people with Long COVID. Researchers asked patients about PEM symptoms and had some patients do an exercise test to see if PEM actually occurred. While 67% of patients reported having PEM symptoms, only 6% actually showed clear PEM after the exercise test. When PEM did occur in Long COVID, it was less severe than what the researchers saw in ME/CFS patients.

Post-Exertional Malaise
E3 PreliminaryPEM ✓PreliminaryMechanisticReviewed

Heightened innate immunity may trigger chronic inflammation, fatigue and post-exertional malaise in ME/CFS.

Che, Xiaoyu, Ranjan, Amit, Guo, Cheng et al.·npj metabolic health and disease·2025

This study examined blood samples and immune responses in ME/CFS patients to understand why they experience extreme fatigue and feeling worse after activity. Researchers found that patients' immune systems overreact to germs, their bodies have trouble producing energy efficiently, and they have several chemical imbalances in their blood. These problems got worse after exercise and matched how sick patients felt.

Metabolic DysfunctionPost-Exertional MalaiseImmune Dysregulation
E3 PreliminaryPEM ✓PreliminaryPreprintPreprintReviewed

Heightened innate immunity may trigger chronic inflammation, fatigue and post-exertional malaise in ME/CFS.

Che, Xiaoyu, Ranjan, Amit, Guo, Cheng et al.·medRxiv : the preprint server for health sciences·2025

This study found that people with ME/CFS may have an overactive immune system that responds too strongly to germs and infections. The research showed problems with how the body produces energy and manages inflammation, and these problems got worse after exercise in ME/CFS patients but not in healthy people. The findings suggest multiple biological systems are working abnormally in ME/CFS, which could help doctors develop better treatments.

Metabolic DysfunctionPost-Exertional MalaiseImmune Dysregulation
E2 ModeratePEM ✗Moderate confidenceObservationalReviewed

Replicated blood-based biomarkers for myalgic encephalomyelitis not explicable by inactivity.

Beentjes, Sjoerd Viktor, Miralles Méharon, Artur, Kaczmarczyk, Julia et al.·EMBO molecular medicine·2025

Researchers found multiple blood markers that distinguish ME/CFS patients from healthy people, including signs of inflammation, insulin problems, and liver issues. Importantly, these differences were NOT caused by patients being physically inactive—they are genuine biological changes related to the disease itself. While no single blood test can diagnose ME/CFS yet, these findings suggest that a combination of blood markers could eventually provide objective diagnosis.

Post-Exertional Malaise
E2 ModeratePEM ✓Higher confidenceLongitudinalReviewed

Incidence and Prevalence of Post-COVID-19 Myalgic Encephalomyelitis: A Report from the Observational RECOVER-Adult Study.

Vernon, Suzanne D, Zheng, Tianyu, Do, Hyungrok et al.·Journal of general internal medicine·2025

This study tracked over 11,000 people who had COVID-19 and about 1,400 who didn't, following them for at least 6 months to see how many developed ME/CFS. Researchers found that people who had COVID-19 were nearly 5 times more likely to develop ME/CFS compared to people who never had COVID-19. About 4.5% of COVID-infected participants developed ME/CFS, compared to only 0.6% of uninfected people.

Post-Exertional Malaise
E3 PreliminaryPEM ✓PreliminaryReview-NarrativeReviewed

Tetrahydrobiopterin in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Friend or Foe?

Rahman, A F M Towheedur, Benko, Anna, Bulbule, Sarojini et al.·Biomolecules·2025

This review article examines a molecule called tetrahydrobiopterin (BH4) and its possible role in ME/CFS, particularly in patients who experience orthostatic intolerance (dizziness or fainting when standing up). The researchers found that BH4 metabolism—the way the body processes this molecule—is not working properly in ME/CFS patients with these symptoms. By understanding how BH4 goes wrong, scientists hope to explain why ME/CFS patients have problems with blood flow to the brain.

BiomarkersPost-Exertional Malaise
E3 PreliminaryPEM ✓PreliminaryMechanisticReviewed

Precision Medicine Study of Post-Exertional Malaise Epigenetic Changes in Myalgic Encephalomyelitis/Chronic Fatigue Patients During Exercise.

Sharma, Sayan, Hodges, Lynette D, Peppercorn, Katie et al.·International journal of molecular sciences·2025

This study looked at how exercise affects the chemical switches on our genes (epigenetics) in ME/CFS patients, particularly during post-exertional malaise (PEM)—the exhaustion that worsens after physical activity. Researchers took blood samples from five ME/CFS patients before, immediately after, and 24-48 hours after an exercise test, and found distinct patterns of genetic changes that were specific to ME/CFS patients and not seen in healthy controls. These changes affected genes related to immune function, inflammation, and blood vessel health, suggesting the body's response to exercise in ME/CFS is fundamentally different at the molecular level.

BiomarkersPost-Exertional MalaiseImmune Dysregulation
E3 PreliminaryPEM ✗Moderate confidenceMechanisticReviewed

Oxidative stress is a shared characteristic of ME/CFS and Long COVID.

Shankar, Vishnu, Wilhelmy, Julie, Curtis, Ellis J et al.·Proceedings of the National Academy of Sciences of the United States of America·2025

Researchers found that both ME/CFS and Long COVID patients have higher levels of oxidative stress—a harmful buildup of unstable molecules—in their immune cells, particularly in a type of white blood cell called memory T cells. The study identified specific problems with how the body clears this oxidative stress and showed that the existing medication metformin might help reduce overgrowth of these immune cells. Importantly, they discovered these problems show different patterns in men and women, suggesting that sex-specific treatment approaches may be needed.

Immune Dysregulation
E3 PreliminaryPEM ?PreliminaryEditorialReviewed

Reframing Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Biological Basis of Disease and Recommendations for Supporting Patients.

Agarwal, Priya, Friedman, Kenneth J·Healthcare (Basel, Switzerland)·2025

This article is a special essay about ME/CFS that was written by a medical student and selected as the best submission in a scholarship competition. It explains what we currently know about how ME/CFS affects the body and offers practical advice for doctors on how to better care for ME/CFS patients. The essay highlights that ME/CFS is a serious, worldwide health problem affecting millions of people, many of whom haven't been properly diagnosed.

Next 20 studies →

Research Collections

Curated groups of studies organised by theme or clinical question.

Neuroinflammation Evidence

PET imaging and other studies providing evidence for brain inflammation in ME/CFS.

Neurology

Metabolism & Mitochondria

Metabolomics and mitochondrial function studies revealing energy metabolism disruption.

Metabolism

Biomarkers

Studies identifying potential biological markers for ME/CFS diagnosis and stratification.

Biomarker

PEM-Specific Research

Studies specifically examining post-exertional malaise, the hallmark symptom of ME/CFS.

PEM