ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

2807 studies

121–140 of 2,807 studies

E2 ModerateCohortPEM not requiredCross-Sectional

Post-COVID-19 Condition Risk Factors and Symptom Clusters and Associations With Return to Pre-COVID-19 Health-Results From a 2021 Multistate Survey.

Konkle, Stacey L, Magleby, Reed, Bonacci, Robert A et al.·Clinical infectious diseases : an official publication of the Infectious Diseases Society of America·2025

This study looked at nearly 30% of people who had COVID-19 in 2020 and developed long-term symptoms afterward (post-COVID condition). Among those with ongoing symptoms, about 77% had not fully recovered to their pre-COVID health 2-15 months later. The researchers found that certain symptom patterns—especially fatigue similar to ME/CFS, upper respiratory problems, and digestive issues—were most strongly linked to prolonged recovery.

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 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 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 requiredCross-Sectional

Concentrations of uremic bacterial metabolites in patients with post-COVID-19 syndrome.

Brigo, Natascha, Mayr, Wolfram, Taenzer, Maja et al.·Frontiers in cellular and infection microbiology·2025

This small study looked at special waste products made by gut bacteria in the urine of people with long COVID, ME/CFS, and healthy people. Researchers found that people with long COVID and ME/CFS had different patterns of these bacterial products compared to healthy controls, and these patterns might be connected to their symptoms like fatigue and post-exertional malaise (feeling much worse after activity).

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 unclearCross-Sectional

Small fiber neuropathy in the post-COVID condition and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Clinical significance and diagnostic challenges.

Azcue, Naiara, Teijeira-Portas, Sara, Tijero-Merino, Beatriz et al.·European journal of neurology·2025

This study found that both long-COVID patients and people with ME/CFS show signs of damage to small nerve fibers in the eyes and altered sensation to heat, compared to healthy people. Researchers used specialized imaging and tests to measure nerve fiber structure and how well patients could detect temperature changes. The findings suggest that small fiber nerve damage may contribute to symptoms like pain and abnormal sensations in these conditions.

Autonomic Nervous System

E2 ModerateBehavioralPEM not requiredObservational

Welfare benefit utilization for people with functional somatic disorder. A population-based cohort study.

Petersen, Marie Weinreich, Wellnitz, Kaare Bro, Carstensen, Tina Birgitte Wisbech et al.·Journal of psychosomatic research·2025

This study looked at how many weeks per year people with functional somatic disorder (FSD)—a condition with persistent physical symptoms that can't be explained by standard medical tests—used welfare benefits compared to people without FSD. Researchers in Denmark tracked about 9,600 people over 14 years and found that people with FSD used significantly more sickness benefits, unemployment benefits, and disability pensions than those without the condition. The findings show that FSD is a seriously disabling condition that affects people's ability to work and support themselves.

E2 ModerateCohortPEM unclearCross-Sectional

HERV activation segregates ME/CFS from fibromyalgia while defining a novel nosologic entity.

Giménez-Orenga, Karen, Martín-Martínez, Eva, Nathanson, Lubov et al.·eLife·2025

This study looked at special genetic materials called human endogenous retroviruses (HERVs) in the blood cells of women with ME/CFS, fibromyalgia, both conditions, or neither. The researchers found that the pattern of which HERVs were active could perfectly distinguish between these four groups—suggesting this could become a reliable blood test to diagnose these conditions. The study also found that ME/CFS patients had specific changes in immune cells that matched how severe their symptoms were.

BiomarkersImmune 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 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

Depressive and anxiety symptoms in current, previous, and no history of ME/CFS: NHIS 2022 analysis.

Sirotiak, Zoe, Adamowicz, Jenna L, Thomas, Emily B K·Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation·2025

This study looked at anxiety and depression in people with ME/CFS using data from a large U.S. health survey. Researchers found that people currently living with ME/CFS reported much higher rates of anxiety and depression compared to people without ME/CFS. Interestingly, people who previously had ME/CFS but have since recovered still reported higher anxiety and depression rates than those who never had the illness, though the rates were lower than for those with current ME/CFS.

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 ModerateCohortPEM unclearCross-Sectional

Genetic variants associated with chronic fatigue syndrome predict population-level fatigue severity and actigraphic measurements.

Liu, Patrick Z, Raizen, David M, Skarke, Carsten et al.·Sleep·2025

This study looked at whether the genetic factors that cause ME/CFS also influence fatigue levels in people without ME/CFS. Researchers compared movement patterns and body temperature rhythms in people with ME/CFS versus healthy controls, then checked if genetic variations linked to ME/CFS were also connected to fatigue in the general population. They found that people with ME/CFS showed significantly less movement and flatter daily temperature patterns, and some genetic variants associated with ME/CFS were also linked to fatigue symptoms in the broader population.

E2 ModerateCohortPEM requiredObservational

Low Vasopressin in Myalgic Encephalomyelitise/Chronic Fatigue Syndrome.

Huhmar, Helena M, Soinne, Lauri S, Bertilson, Bo Christer et al.·Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists·2025

This study found that most people with ME/CFS have abnormally low levels of vasopressin, a hormone that helps your body control water balance and blood volume. The researchers measured this hormone and fluid markers in over 100 ME/CFS patients and discovered that 82% had vasopressin levels below the detectable range. This may help explain why many ME/CFS patients experience excessive thirst, frequent urination, and dizziness when standing up.

Autonomic Nervous System

E2 ModerateCohortPEM unclearCross-Sectional

Circulating cell-free RNA signatures for the characterization and diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome.

Gardella, Anne E, Eweis-LaBolle, Daniel, Loy, Conor J et al.·Proceedings of the National Academy of Sciences of the United States of America·2025

Researchers analyzed tiny pieces of RNA floating in the blood of people with ME/CFS and compared them to healthy people. They used a computer program to identify a pattern of these RNA pieces that could help diagnose ME/CFS with 77% accuracy. The study found that people with ME/CFS have different levels of immune cells releasing material into their blood, suggesting the immune system is behaving differently.

Immune System

E2 ModerateCohortPEM requiredCross-Sectional

Possible Racial Disparities in the Diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Jones, Chloe Lisette, Younger, Jarred·International journal of environmental research and public health·2025

This study looked at whether Black people and other racial minorities with ME/CFS symptoms are less likely to receive an official diagnosis compared to white people. Researchers surveyed over 1,100 people and found that white respondents were nearly three times more likely to be diagnosed with ME/CFS than non-white respondents, even when they had similar symptoms. The findings suggest that racial bias may be affecting who gets diagnosed with ME/CFS.

E2 ModerateCohortPEM not requiredCase-Control

Alterations in gut microbiota and associated metabolites in patients with chronic fatigue syndrome.

Cheng, Xinxin, Wang, Wenkuan, Xu, Tingting et al.·Scientific reports·2025

This study looked at the bacteria living in the gut of people with ME/CFS compared to healthy people, and found that ME/CFS patients have fewer types of bacteria and lower levels of helpful compounds called short-chain fatty acids (SCFAs) that bacteria produce. The study found that people with ME/CFS who eat more fiber have higher levels of these beneficial compounds, suggesting diet may help restore some of the bacterial imbalances seen in ME/CFS.

Energy Metabolism

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 unclearObservational

Functional and internalizing disorders co-aggregate with cardiometabolic and immune-related diseases within families: a population-based cohort study.

Steen, Olivier D, Bos, Martje, van Ockenburg, Sonja L et al.·BMC medicine·2025

This study found that ME/CFS, fibromyalgia, and irritable bowel syndrome tend to run in families alongside conditions like depression, anxiety, autoimmune diseases, and metabolic disorders. Researchers analyzed data from over 166,000 people in a Dutch population cohort to understand whether these conditions share common inherited risk factors. The findings suggest that the causes of functional disorders like ME/CFS may overlap with the causes of immune and metabolic diseases, which could point to new treatment approaches.

Immune System

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Evidence Atlas

Evidence browser

Post-COVID-19 Condition Risk Factors and Symptom Clusters and Associations With Return to Pre-COVID-19 Health-Results From a 2021 Multistate Survey.

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

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

Concentrations of uremic bacterial metabolites in patients with post-COVID-19 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).

Small fiber neuropathy in the post-COVID condition and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Clinical significance and diagnostic challenges.

Welfare benefit utilization for people with functional somatic disorder. A population-based cohort study.

HERV activation segregates ME/CFS from fibromyalgia while defining a novel nosologic entity.

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

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

Depressive and anxiety symptoms in current, previous, and no history of ME/CFS: NHIS 2022 analysis.

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

Genetic variants associated with chronic fatigue syndrome predict population-level fatigue severity and actigraphic measurements.

Low Vasopressin in Myalgic Encephalomyelitise/Chronic Fatigue Syndrome.

Circulating cell-free RNA signatures for the characterization and diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome.

Possible Racial Disparities in the Diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Alterations in gut microbiota and associated metabolites in patients with chronic fatigue syndrome.

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

Functional and internalizing disorders co-aggregate with cardiometabolic and immune-related diseases within families: a population-based cohort study.

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