Evidence browser

E2 ModerateCohortPEM not requiredObservational

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

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

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.

E2 ModerateCohortPEM unclearRegistry-Resource

Unequal access to diagnosis of myalgic encephalomyelitis in England.

Samms, Gemma Louise, Ponting, Chris P·BMC public health·2025

This study examined NHS records from England to understand how many people have ME/CFS and whether diagnosis is fair across different groups. Researchers found that about 100,000 people in England have been officially diagnosed with ME/CFS, but the actual number may be much higher—around 404,000 in the UK. The diagnosis rates varied significantly depending on gender, age, ethnicity, and where people live, suggesting some patients are being missed.

Diagnostics

Chronic fatigue syndrome, depression, and anxiety symptoms due to relapsing-remitting multiple sclerosis are associated with reactivation of Epstein-Barr virus and Human Herpesvirus 6.

Maes, Michael, Almulla, Abbas F, Vojdani, Elroy et al.·Neuro endocrinology letters·2025

This study looked at whether reactivation of two common viruses—Epstein-Barr virus (EBV) and Human herpesvirus 6 (HHV-6)—are connected to fatigue, depression, and anxiety in people with a type of multiple sclerosis called RRMS. Researchers measured immune responses (antibodies) to these viruses in MS patients and healthy controls, and found that higher antibody levels were strongly linked to worse fatigue and mood symptoms. The findings suggest that when these dormant viruses become active in the body, they may trigger or worsen fatigue and psychiatric symptoms.

E2 ModerateCohortPEM not requiredCase-Control

Diagnosis of chronic fatigue syndrome using beat-to-beat autonomic measurements.

Kujawski, Sławomir, Tabisz, Hanna, Morten, Karl J et al.·Journal of translational medicine·2025

Researchers used artificial intelligence to analyze how the heart and nervous system behave differently in ME/CFS patients compared to healthy people. By measuring heart rate changes beat-by-beat, they found a pattern that could identify ME/CFS patients with 89% accuracy. The key differences included a less responsive vagal nerve (which normally calms the body), a more active stress response in blood vessels, and less efficient heart pumping.

E2 ModerateBehavioralPEM not requiredObservational

Familial coaggregation and shared familiality of functional and internalizing disorders in the Lifelines cohort.

Bos, Martje, Monden, Rei, Wray, Naomi R et al.·Psychological medicine·2025

This study looked at whether ME/CFS, irritable bowel syndrome, and fibromyalgia run in families, and whether they share common causes with depression and anxiety disorders. Researchers studied over 150,000 people in the Netherlands and found that these conditions do tend to cluster in families—if a relative has one of these conditions, your risk of having it is higher. ME/CFS showed the strongest family connection and was most closely linked to depression.

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

Leveraging Explainable Automated Machine Learning (AutoML) and Metabolomics for Robust Diagnosis and Pathophysiological Insights in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Yagin, Fatma Hilal, Colak, Cemil, Al-Hashem, Fahaid et al.·Diagnostics (Basel, Switzerland)·2025

Researchers used advanced computer learning and blood tests to find chemical markers that could help diagnose ME/CFS. They analyzed 888 different chemicals in blood samples from 106 ME/CFS patients and 91 healthy people, and found a pattern of chemical imbalances that correctly identified ME/CFS patients 87% of the time. The key chemical imbalances involved energy production in cells, inflammation, and gut health—areas that have long been suspected in ME/CFS.

Energy Metabolism

The Relation Between Cardiac Output and Cerebral Blood Flow in ME/CFS Patients with a POTS Response During a Tilt Test.

van Campen, C Linda M C, Visser, Frans C·Journal of clinical medicine·2025

When people with ME/CFS and POTS stand up, their blood pressure and heart rate don't respond normally, causing symptoms like dizziness and fatigue. This study looked at 260 ME/CFS patients during a tilt test to understand how the heart's output of blood relates to blood flow in the brain. The researchers found two different patterns: about two-thirds of patients showed their brain blood flow dropped at roughly the same rate as their heart's output decreased, while about one-third had a different pattern where their heart was racing but their heart output wasn't dropping as much, and their brain blood flow didn't follow the expected pattern.

Awareness and Perception of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Among Pain Specialists: A Questionnaire-Based Study.

Uygun, Gürsan Güneş, Gözükızıl, Salim Taner, Bilen, Ayşegül·Cureus·2025

This study asked pain doctors in Turkey about their knowledge of ME/CFS and how they evaluate and treat patients with the condition. The results show that many pain specialists aren't familiar with ME/CFS, and some hold misconceptions—like thinking it's a type of depression or that intense exercise will help. This matters because pain doctors could potentially help ME/CFS patients, but they need better education about the condition first.

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.

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 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 requiredCase-Control

Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis.

Moezzi, Atefeh, Ushenkina, Anastasiya, Widgren, Anna et al.·Journal of translational medicine·2025

Researchers studied a protein called haptoglobin in people with ME/CFS and found it may be connected to post-exertional malaise (that worsening of symptoms after activity) and brain fog. They discovered that certain genetic variations of this protein were more common in ME/CFS patients, and those variations were linked to worse symptoms and cognitive problems. The study suggests haptoglobin could be a useful marker to help doctors understand why ME/CFS symptoms vary between patients.

BiomarkersPost-Exertional Malaise

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 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.

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.

Peripheral Levels of Selected Biomarkers in Patients with Post-Sarcoidosis Chronic Fatigue Syndrome.

Małujło-Balcerska, Elżbieta, Bączek, Karol, Górski, Witold et al.·Journal of inflammation research·2025

This study looked at 71 people with sarcoidosis (a disease that causes inflammation) to understand why some feel extremely tired even after their disease improves. Researchers measured inflammation markers in the blood and found that people with lingering fatigue had higher levels of a protein called IL-6 compared to those without fatigue. The findings suggest that low-grade inflammation may be keeping people fatigued even when their disease appears to be under control.

Autonomic symptom burden, comorbidities and quality of life in women with Hypermobility Spectrum Disorders and hypermobile Ehlers-Danlos syndrome.

Collins Hutchinson, Meagan L, Liang, Emily, Fuster, Emily et al.·Autonomic neuroscience : basic & clinical·2025

This study looked at 84 women with connective tissue disorders (HSD/h-EDS) to understand how much autonomic nervous system problems they experience and how these affect their quality of life. The researchers found that these women had severe autonomic symptoms, with nearly 60% also having POTS and about 26% having ME/CFS. Overall, their quality of life was significantly worse than patients with other serious conditions like multiple sclerosis or rheumatoid arthritis.