ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

621–640 of 738 studies

E3 PreliminaryGuidelinePEM requiredGuideline

Myalgic encephalomyelitis: International Consensus Criteria.

Journal of internal medicine·2017

This guideline establishes internationally agreed-upon criteria for diagnosing ME/CFS, helping doctors around the world recognize the condition consistently. It brings together expert knowledge to create clear standards for who has ME/CFS based on symptoms like post-exertional malaise (worsening after activity), sleep problems, cognitive difficulties, and pain. Having a shared definition makes it easier for patients to get accurate diagnoses and for researchers to study the same condition across different countries.

Post-Exertional Malaise

E3 PreliminaryGuidelinePEM requiredGuideline

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Diagnosis and Management in Young People: A Primer.

Rowe, Peter C, Underhill, Rosemary A, Friedman, Kenneth J et al.·Frontiers in pediatrics·2017

This guide helps doctors understand and diagnose ME/CFS in children and teenagers. ME/CFS causes extreme tiredness and makes it hard for young people to do physical or mental activities—with symptoms often getting worse after even small efforts and lasting for days or longer. The guide explains that there is no single test for ME/CFS, so doctors must diagnose it based on symptoms and by ruling out other conditions, and recommends that treatment focus on finding the right balance between rest and activity.

Post-Exertional Malaise

E3 PreliminaryCohortPEM not requiredCase-Control

Two hundreds cases of ASIA syndrome following silicone implants: a comparative study of 30 years and a review of current literature.

Colaris, Maartje J L, de Boer, Mintsje, van der Hulst, Rene R et al.·Immunologic research·2017

This study compared 200 patients with silicone breast implants who developed autoimmune and inflammatory symptoms (a condition called ASIA) across two time periods—100 patients in 2014 and 100 historical patients from the 1980s–1990s. The researchers found that the symptoms remained similar over 30 years, including fatigue, joint pain, brain fog, and fever. About half of the patients who had their implants removed experienced symptom improvement.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM requiredMechanistic

Neural consequences of post-exertion malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Cook, Dane B, Light, Alan R, Light, Kathleen C et al.·Brain, behavior, and immunity·2017

This study examined what happens in the brains of ME/CFS patients after exercise. Researchers asked 15 patients and 15 healthy people to exercise for 30 minutes, then used brain imaging to see how their brains worked before and 24 hours after exercise. ME/CFS patients' symptoms got much worse after exercise, their thinking and memory got worse, and their brain activity changed in specific ways—showing that exercise triggered real, measurable changes in how their brains functioned.

Post-Exertional Malaise

E3 PreliminaryReviewPEM unclearReview-Narrative

Mechanisms Explaining Muscle Fatigue and Muscle Pain in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a Review of Recent Findings.

Gerwyn, Morris, Maes, Michael·Current rheumatology reports·2017

This review examines why ME/CFS patients experience muscle fatigue and pain. Researchers found that several biological problems may contribute to these symptoms: damaged cellular energy factories (mitochondria), harmful stress molecules building up in the body, and reduced production of protective proteins. These problems together may explain why ME/CFS patients get tired quickly and struggle with exercise.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM unclearMechanistic

Detection of Urine Metabolites in a Rat Model of Chronic Fatigue Syndrome before and after Exercise.

Shao, Changzhuan, Ren, Yiming, Wang, Zinan et al.·BioMed research international·2017

Researchers used rats exposed to stress and exercise to model ME/CFS and then measured chemicals in their urine before and after exercise. They found abnormalities in how the rats' bodies produce energy and process hormones, particularly in molecules called sphingosine and a hormone precursor called 21-hydroxypregnenolone. These findings suggest that ME/CFS may involve disrupted energy metabolism and problems with the body's stress-response system.

Energy MetabolismImmune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Exercise-induced mitochondrial dysfunction: a myth or reality?

Ostojic, Sergej M·Clinical science (London, England : 1979)·2016

Exercise is usually good for your cells' energy factories (mitochondria), but this review asks whether extremely intense or exhausting exercise might actually damage them instead. The authors explore how very hard exercise could harm mitochondrial function and suggest this might explain some cases of chronic fatigue syndrome and muscle problems.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM requiredMechanistic

Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy/chronic fatigue syndrome.

Fluge, Øystein, Mella, Olav, Bruland, Ove et al.·JCI insight·2016

This study found that people with ME/CFS have abnormal patterns of amino acids (building blocks of protein) in their blood, suggesting their bodies struggle to produce energy efficiently through normal metabolic pathways. The research identified a specific problem with an enzyme called pyruvate dehydrogenase that helps convert fuel into cellular energy, and showed that cells from ME/CFS patients produce excess lactate (a byproduct of incomplete energy metabolism) when stressed. These findings help explain why ME/CFS patients experience exhaustion after exertion and poor recovery.

Energy MetabolismPost-Exertional Malaise

E3 PreliminaryMechanismPEM unclearMechanistic

Gene Expression in Response to Exercise in Patients with Chronic Fatigue Syndrome: A Pilot Study.

Keech, Andrew, Vollmer-Conna, Ute, Barry, Benjamin K et al.·Frontiers in physiology·2016

Researchers studied whether a single 25-minute exercise session changed the activity of specific genes in white blood cells of ME/CFS patients compared to healthy people. Although ME/CFS patients reported significantly worsened fatigue after exercise, the researchers found no major changes in the 19 genes they measured in either group, suggesting that post-exertional fatigue may not be caused by these particular genes switching on or off.

Post-Exertional Malaise

E3 PreliminaryCohortPEM requiredCase-Control

A Pair of Identical Twins Discordant for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Differ in Physiological Parameters and Gut Microbiome Composition.

Giloteaux, Ludovic, Hanson, Maureen R, Keller, Betsy A·The American journal of case reports·2016

This study compared two identical twins—one with ME/CFS and one without—to understand what causes the illness. The affected twin showed reduced exercise capacity, abnormal responses to physical exertion, and differences in immune markers and gut bacteria compared to the healthy twin. These findings suggest that ME/CFS involves problems with how the body responds to exercise and changes in the gut bacteria that may trigger inflammation.

Gut MicrobiomeImmune SystemPost-Exertional Malaise

E3 PreliminaryTrialPEM not requiredRCT

Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome.

Rowe, Peter C, Fontaine, Kevin R, Lauver, Megan et al.·PloS one·2016

Researchers tested whether stretching nerves and soft tissues in the legs—by doing a simple straight leg raise test—could trigger or worsen ME/CFS symptoms. Patients with ME/CFS who received the real stretch experienced more pain, concentration problems, and lightheadedness during and 24 hours after the test, compared to those who received a fake stretch and compared to healthy people. This suggests that physical strain on nerves and tissues may be one reason why ME/CFS symptoms get worse with activity.

Post-Exertional Malaise

E3 PreliminaryReviewPEM unclearReview-Narrative

Understanding Muscle Dysfunction in Chronic Fatigue Syndrome.

Rutherford, Gina, Manning, Philip, Newton, Julia L·Journal of aging research·2016

This review examined research showing that people with ME/CFS may have problems with how their muscles produce and use energy. Specifically, their muscles appear to rely too heavily on a less efficient energy pathway (lactate dehydrogenase) during and after exercise, and they have difficulty clearing the acidic byproducts that build up. These muscle-level energy problems could explain why ME/CFS patients experience severe fatigue and difficulty maintaining physical activity.

Post-Exertional Malaise

E3 PreliminaryDiagnosticPEM requiredMethods-Paper

Assessment of ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome): A Case Study for Health Care Providers.

Brimmer, Dana J, Jones, James F, Boneva, Roumiana et al.·MedEdPORTAL : the journal of teaching and learning resources·2016

This study created an educational course to help medical students, physician assistants, and nursing students better understand ME/CFS and how to care for patients with this condition. The course used videos and slide presentations to teach about ME/CFS symptoms, diagnosis, and management. Students who completed the course showed improved knowledge about ME/CFS and developed more empathy for patients living with this illness.

Post-Exertional Malaise

E3 PreliminaryCommentaryPEM requiredEditorial

Living with ME/CFS. challenge for scientists?

Weiler, John J A·Neuro endocrinology letters·2015

This case describes a person with ME/CFS for 19 years who experienced an unusual pattern: they could run 10 kilometers without problems, but later that same day, 30 minutes of browsing for books triggered severe exhaustion, muscle pain, and brain fog lasting into the next day. This puzzling difference highlights how ME/CFS symptoms don't always follow expected patterns and suggests that exercise intolerance in ME/CFS may be more complex than previously thought.

Post-Exertional Malaise

E3 PreliminaryReviewPEM requiredReview-Narrative

Review of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: an evidence-based approach to diagnosis and management by clinicians.

Bested, Alison C, Marshall, Lynn M·Reviews on environmental health·2015

This review helps doctors understand ME/CFS better by explaining what it is, how to diagnose it, and how to treat it. ME/CFS is a serious illness that causes extreme tiredness, brain fog, pain, and sleep problems that get worse after physical activity. The review emphasizes that pacing activities—carefully balancing rest with gentle exercise—is one of the most important strategies patients can use to manage their symptoms and avoid crashes.

Post-Exertional Malaise

E3 PreliminaryDiagnosticPEM requiredMethods-Paper

Problems in defining post-exertional malaise.

Jason, Leonard A, Evans, Meredyth, So, Suzanna et al.·Journal of prevention & intervention in the community·2015

This study looked at how post-exertional malaise (PEM)—the characteristic worsening of symptoms after physical or mental effort—is measured in ME/CFS patients. Researchers asked 32 people with CFS to answer survey questions about PEM and found that small changes in how questions are worded can change whether someone is diagnosed with PEM. This suggests that the current ways of diagnosing this condition may not be reliable or consistent.

Post-Exertional Malaise

E3 PreliminaryReviewPEM unclearReview-Narrative

Exercise, not to exercise, or how to exercise in patients with chronic pain? Applying science to practice.

Daenen, Liesbeth, Varkey, Emma, Kellmann, Michael et al.·The Clinical journal of pain·2015

This review examines how exercise affects people with chronic pain, including ME/CFS. While exercise helps many chronic pain conditions, some patients—especially those with ME/CFS, fibromyalgia, and chronic whiplash—experience worsening symptoms or 'crashes' after exercising. The authors emphasize that exercise programs need to be carefully tailored to each person, with proper recovery time built in, rather than using a one-size-fits-all approach.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredCross-Sectional

The relationship between interleukin-6 in saliva, venous and capillary plasma, at rest and in response to exercise.

Cullen, T, Thomas, A W, Webb, R et al.·Cytokine·2015

Researchers measured a protein called IL-6 that the body produces during exercise and inflammation. They took samples from blood and saliva before and after exercise to see if IL-6 levels changed and whether different measurement methods gave similar results. They found that IL-6 increased in blood after exercise, but saliva samples did not show this increase, suggesting saliva may not be a reliable way to track this immune marker.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredMechanistic

Abnormalities of AMPK activation and glucose uptake in cultured skeletal muscle cells from individuals with chronic fatigue syndrome.

Brown, Audrey E, Jones, David E, Walker, Mark et al.·PloS one·2015

Researchers grew muscle cells from ME/CFS patients and healthy people in the lab and stimulated them electrically to mimic exercise. They found that muscle cells from ME/CFS patients didn't respond normally to this simulated exercise: they failed to activate a key energy-sensing protein (AMPK) and didn't increase glucose uptake like healthy cells did. This suggests the problem may be rooted in how the muscle cells themselves are built or programmed, not just from being inactive.

Energy MetabolismPost-Exertional Malaise

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Effects of Time Frame on the Recall Reliability of CFS Symptoms.

Evans, Meredyth, Jason, Leonard A·Evaluation & the health professions·2015

This study looked at how accurately people with ME/CFS can remember and report their symptoms depending on how far back they think about (one week, one month, or six months). Researchers found that asking patients to recall symptoms from the past six months was most reliable for most symptoms, though joint pain was best recalled over one month. This matters because doctors need to know the best time frame to ask about when diagnosing ME/CFS.

Post-Exertional Malaise

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Myalgic encephalomyelitis: International Consensus Criteria.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Diagnosis and Management in Young People: A Primer.

Two hundreds cases of ASIA syndrome following silicone implants: a comparative study of 30 years and a review of current literature.

Neural consequences of post-exertion malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Mechanisms Explaining Muscle Fatigue and Muscle Pain in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a Review of Recent Findings.

Detection of Urine Metabolites in a Rat Model of Chronic Fatigue Syndrome before and after Exercise.

Exercise-induced mitochondrial dysfunction: a myth or reality?

Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy/chronic fatigue syndrome.

Gene Expression in Response to Exercise in Patients with Chronic Fatigue Syndrome: A Pilot Study.

A Pair of Identical Twins Discordant for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Differ in Physiological Parameters and Gut Microbiome Composition.

Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome.

Understanding Muscle Dysfunction in Chronic Fatigue Syndrome.

Assessment of ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome): A Case Study for Health Care Providers.

Living with ME/CFS. challenge for scientists?

Review of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: an evidence-based approach to diagnosis and management by clinicians.

Problems in defining post-exertional malaise.

Exercise, not to exercise, or how to exercise in patients with chronic pain? Applying science to practice.

The relationship between interleukin-6 in saliva, venous and capillary plasma, at rest and in response to exercise.

Abnormalities of AMPK activation and glucose uptake in cultured skeletal muscle cells from individuals with chronic fatigue syndrome.

Effects of Time Frame on the Recall Reliability of CFS Symptoms.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research