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.

94 studies

NewestEvidence
E3 PreliminaryPEM ✗Weak / uncertainReviewed

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
E0 ConsensusPEM ✗Moderate confidenceReviewed

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 ✓PreliminaryReviewed

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
E0 ConsensusPEM ?Moderate confidenceReviewed

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): diagnosis and management.

Fan, Jin, Jiao, Jiao, Chang, Hai-Qing et al.·Journal of translational medicine·2025

This comprehensive review examines how ME/CFS is diagnosed and treated based on current medical knowledge. The authors found that ME/CFS is caused by problems with the immune system, energy production in cells, and brain inflammation, but there are currently no definitive blood tests to confirm the disease. Treatment options include both medication approaches (targeting immune dysfunction and cell energy) and non-medication strategies like activity pacing and cognitive behavioral therapy, though doctors now recognize that exercise programs can actually harm some patients.

BiomarkersNeuroinflammationImmune Dysregulation
E3 PreliminaryPEM ?Moderate confidenceReviewed

Mitochondrial Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Syed, Abu Mohammad, Karius, Alexander K, Ma, Jin et al.·Physiology (Bethesda, Md.)·2025

This review examines how mitochondria—the parts of cells that produce energy—may not be working properly in ME/CFS patients. The authors suggest that problems with energy production in cells could explain why people with ME/CFS feel severely exhausted after physical activity. They also note that similar energy problems appear in long COVID, which suggests both conditions may share a common underlying cause.

Long COVID OverlapPost-Exertional Malaise
E3 PreliminaryPEM ?PreliminaryReviewed

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.

E0 ConsensusPEM ?Moderate confidenceReviewed

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
E2 ModeratePEM ✗Moderate confidenceReviewed

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
E0 ConsensusPEM ✓Moderate confidenceReviewed

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
E3 PreliminaryPEM ✓PreliminaryReviewed

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
E0 ConsensusPEM ✓Moderate confidenceReviewed

Key Pathophysiological Role of Skeletal Muscle Disturbance in Post COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Accumulated Evidence.

Scheibenbogen, Carmen, Wirth, Klaus J·Journal of cachexia, sarcopenia and muscle·2025

This review brings together recent research showing that ME/CFS involves problems in the muscles themselves, particularly damage to mitochondria (the energy-producing structures inside cells) and an imbalance of salt and calcium in muscle tissue. When muscles don't get enough oxygen, they switch to a less efficient way of making energy, which causes sodium (salt) to build up inside cells, triggering calcium overload that damages mitochondria. This cascade of damage may explain why patients experience severe fatigue and feel much worse after exercise.

Post-Exertional Malaise
E3 PreliminaryPEM ✓PreliminaryReviewed

Dissecting the genetic complexity of myalgic encephalomyelitis/chronic fatigue syndrome via deep learning-powered genome analysis.

Zhang, Sai, Jahanbani, Fereshteh, Chander, Varuna et al.·medRxiv : the preprint server for health sciences·2025

Researchers used advanced artificial intelligence to analyze the genes of ME/CFS patients and discovered 115 genes that may contribute to the disease. They found that people with ME/CFS have lower levels of these risk genes active in their immune cells and nervous system. This genetic analysis could eventually help doctors diagnose ME/CFS more accurately and identify new treatment targets.

BiomarkersCognitive ImpairmentPost-Exertional MalaiseImmune Dysregulation
E0 ConsensusPEM ?Moderate confidenceReviewed

Cognitive Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-Aetiology and Potential Treatments.

Bansal, Amolak Singh, Seton, Katharine A, Brooks, Jonathan C W et al.·International journal of molecular sciences·2025

Many ME/CFS patients experience brain fog and difficulty concentrating, which can be as disabling as physical symptoms. This review examined how ongoing low-level inflammation and viral activity in the body may damage thinking and memory by affecting blood flow and nerve function in the brain. The researchers suggest that treating inflammation, controlling viral reactivation, and improving how cells produce energy could potentially help restore cognitive function.

NeuroinflammationImmune Dysregulation
E0 ConsensusPEM ?Moderate confidenceReviewed

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.

E2 ModeratePEM ✓Higher confidenceReviewed

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 ✓PreliminaryReviewed

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 ?PreliminaryReviewed

Heat vs. Fatigue: Hyperthermia as a Possible Treatment Option for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Hochecker, Barbara, Matt, Katja, Scherer, Melanie et al.·International journal of molecular sciences·2025

This small pilot study looked at how heat treatment (whole-body hyperthermia) affected immune cells from 9 people with ME/CFS. Researchers found that ME/CFS patients' cells showed signs of being overactive in certain ways compared to healthy people, and that heat treatment seemed to help normalize some of these cellular patterns. While these early results are promising, much larger studies are needed to confirm whether heat therapy could be a useful treatment.

Immune Dysregulation
E0 ConsensusPEM ✓Moderate confidenceReviewed

Differential Characteristics and Comparison Between Long-COVID Syndrome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Ivanovska, Mariya, Homadi, Maysam Salim, Angelova, Gergana et al.·Biomedicines·2025

This review compared Long-COVID (illness after COVID-19) and ME/CFS (chronic fatigue syndrome), which share similar symptoms like extreme tiredness, difficulty thinking clearly, and problems with the nervous system. While both conditions likely involve immune system problems, viral persistence, and blood vessel issues, they appear to have some differences in how they develop. Currently, there is no cure for either condition, though lifestyle management and rehabilitation help some people.

Cognitive ImpairmentPost-Exertional MalaiseImmune Dysregulation
E3 PreliminaryPEM ✓PreliminaryReviewed

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 confidenceReviewed

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
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