ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

2781 studies

81–100 of 2,781 studies

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 ModerateBehavioralPEM not requiredCross-Sectional

Network structure of functional somatic symptoms.

Litzenburger, Alexandra, Rothacher, Yannick, Hanusch, Kay-Uwe et al.·Journal of psychosomatic research·2025

This study looked at how symptoms cluster together in people with functional somatic syndromes (like ME/CFS, fibromyalgia, and others). Researchers surveyed over 3,000 young adults and used network analysis to map which symptoms tend to appear together. They found that fatigue and depression are particularly important symptoms that connect different symptom groups, and identified ten distinct clusters of related symptoms.

Pain and SensitizationCognitive Impairment

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 ModerateBehavioralPEM unclearCase-Control

Bipolar spectrum, hypothyroidism, and their association with chronic fatigue/myalgic encephalomyelitis-like syndrome in long COVID: could they be identified as early determinants?

Tusconi, Massimo, Dursun, Serdar M, Pegreffi, Francesco et al.·Frontiers in psychiatry·2025

This study found that people with long COVID who developed ME/CFS-like symptoms were much more likely to have had hypothyroidism (an underactive thyroid) or bipolar spectrum disorders before getting sick compared to people from before the pandemic. The researchers suggest these pre-existing conditions might make someone more vulnerable to developing ME/CFS after COVID-19, possibly because they affect sleep rhythms and immune function.

E2 ModerateBehavioralPEM not requiredLongitudinal

Risk factors for fatigue severity in the post-COVID-19 condition: A prospective controlled cohort study of nonhospitalised adolescents and young adults.

Selvakumar, Joel, Havdal, Lise Beier, Brodwall, Elias Myrstad et al.·Brain, behavior, & immunity - health·2025

This study followed young people (ages 12–25) who had COVID-19 to understand why some develop long-lasting fatigue while others recover well. Researchers found that how severe symptoms were in the first few weeks after infection—and psychological factors like loneliness and worry—were much stronger predictors of ongoing fatigue at 6 months than any blood test or physical measure. Surprisingly, whether someone actually had COVID-19 made only a small difference; other life circumstances and emotional stress mattered more.

E2 ModerateCohortPEM not requiredCross-Sectional

Abnormal breathing patterns and hyperventilation are common in patients with chronic fatigue syndrome during exercise.

Mancini, Donna M, Brunjes, Danielle L, Cook, Dane et al.·Frontiers in medicine·2025

Researchers studied how patients with ME/CFS breathe during exercise and found that many breathe abnormally in ways that healthy people do not. Specifically, 42% of ME/CFS patients showed irregular breathing patterns, and 32% were breathing too fast and too deeply (hyperventilation). These breathing problems were much more common in ME/CFS patients than in the healthy control group, suggesting that abnormal breathing may be contributing to the fatigue and breathlessness patients experience.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearLongitudinal

Functional olfactory impairment and fatigue in post-COVID-19 syndrome including ME/CFS - a longitudinal prospective observational study.

Meyer-Arndt, Lil, Pierchalla, Greta, Mödl, Lukas et al.·Brain, behavior, & immunity - health·2025

This study followed 45 long-COVID patients over 28 months to understand the connection between smell problems and fatigue, including those who developed ME/CFS. Researchers tested how well patients could smell (detecting scent strength, telling scents apart, and identifying them) and measured their fatigue, thinking ability, and physical strength. Most patients' smell improved over time, but problems with identifying specific smells lasted the longest, and patients with better smell discrimination at the start tended to feel better and function better after 20 months.

Cognitive Impairment

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

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 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 unclearCase-Control

People with Long COVID and ME/CFS Exhibit Similarly Impaired Dexterity and Bimanual Coordination: A Case-Case-Control Study.

Sanal-Hayes, Nilihan E M, Hayes, Lawrence D, Mclaughlin, Marie et al.·The American journal of medicine·2025

This study tested hand coordination and fine motor skills in people with long COVID and ME/CFS using a simple pegboard task where participants place small pegs into holes as quickly and accurately as possible. Both patient groups performed similarly to each other but notably worse than healthy people, suggesting that problems with hand coordination and dexterity are common to both conditions. The findings highlight that these motor difficulties deserve specific medical attention and treatment in both long COVID and ME/CFS patients.

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

Medication use and symptomology in North American women with myalgic encephalomyelitis/chronic fatigue syndrome.

Pochakom, Angela, MacNevin, Gillian, Madden, Robyn F et al.·Frontiers in medicine·2025

This study surveyed 135 women with ME/CFS in North America to understand what medications they use and how these relate to their symptoms and daily functioning. Most participants were taking an average of 3 medications for ME/CFS-related symptoms, with pain medications being the most common, followed by psychiatric and immune-related medications. Interestingly, the study found a U-shaped pattern: both people using very few medications and those using many medications reported lower physical functioning, while moderate medication use was associated with better functioning.

Interventions

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 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 unclearCross-Sectional

Provocation of brachial plexus and systemic symptoms during the elevated arm stress test in individuals with myalgic encephalomyelitis/chronic fatigue syndrome or idiopathic chronic fatigue.

Edwards, Charles C, Byrnes, Julia M, Broussard, Camille A et al.·Journal of translational medicine·2025

Researchers tested whether a simple arm position exercise (holding arms overhead and opening/closing fists) could trigger symptoms in ME/CFS patients who struggle with overhead activities. They found that nearly all patients (97%) developed arm symptoms like pain, numbness, or heaviness during the test, and 41% also experienced whole-body symptoms like dizziness, brain fog, or a racing heart. This suggests that some ME/CFS patients may have nerve compression issues in their shoulders or neck that worsen with certain arm positions.

Autonomic Nervous System

E2 ModerateCohortPEM unclearObservational

Predisposing and Precipitating Factors in Epstein-Barr Virus-Caused Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Jason, Leonard A, Katz, Ben Z·Microorganisms·2025

This study followed college students before and after they got infectious mononucleosis (IM) caused by Epstein-Barr virus to understand why some people develop ME/CFS afterward while others recover. Researchers collected health information and blood samples from students at three time points: before they got sick, shortly after their IM diagnosis, and six months later. By studying these young people over time, the researchers identified certain factors present before and during the infection that seemed to predict who would develop ME/CFS rather than recover.

E2 ModerateCohortPEM unclearObservational

Immune Signatures in Post-Acute Sequelae of COVID-19 (PASC) and Myalgia/Chronic Fatigue Syndrome (ME/CFS): Insights from the Fecal Microbiome and Serum Cytokine Profiles.

Tobi, Martin, Chaudhari, Diptaraj, Ryan, Elizabeth P et al.·Biomolecules·2025

Researchers compared gut bacteria and immune molecules in the blood of people with long COVID and chronic fatigue syndrome. They found that people with these conditions have unusual patterns of gut bacteria and different levels of immune signaling molecules compared to healthy controls. These differences suggest the immune system and gut health may play a role in why some people develop long-lasting fatigue after infection.

Immune 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.

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Evidence browser

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

Network structure of functional somatic symptoms.

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

Bipolar spectrum, hypothyroidism, and their association with chronic fatigue/myalgic encephalomyelitis-like syndrome in long COVID: could they be identified as early determinants?

Risk factors for fatigue severity in the post-COVID-19 condition: A prospective controlled cohort study of nonhospitalised adolescents and young adults.

Abnormal breathing patterns and hyperventilation are common in patients with chronic fatigue syndrome during exercise.

Functional olfactory impairment and fatigue in post-COVID-19 syndrome including ME/CFS - a longitudinal prospective observational study.

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

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.

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.

People with Long COVID and ME/CFS Exhibit Similarly Impaired Dexterity and Bimanual Coordination: A Case-Case-Control Study.

Low Vasopressin in Myalgic Encephalomyelitise/Chronic Fatigue Syndrome.

Medication use and symptomology in North American women with myalgic encephalomyelitis/chronic fatigue syndrome.

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

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

Provocation of brachial plexus and systemic symptoms during the elevated arm stress test in individuals with myalgic encephalomyelitis/chronic fatigue syndrome or idiopathic chronic fatigue.

Predisposing and Precipitating Factors in Epstein-Barr Virus-Caused Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Immune Signatures in Post-Acute Sequelae of COVID-19 (PASC) and Myalgia/Chronic Fatigue Syndrome (ME/CFS): Insights from the Fecal Microbiome and Serum Cytokine Profiles.

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

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