ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

1201–1220 of 6,188 studies

E2 ModerateCohortPEM not requiredCross-Sectional

Prevalence and severity of neurologic symptoms in Long-COVID and the role of pre-existing conditions, hospitalization, and mental health.

Huff, Hanalise V, Roberts, Henry, Bartrum, Elizabeth et al.·Frontiers in neurology·2025

This study looked at neurological symptoms in 213 people with Long-COVID, examined 8 months after infection. Researchers found that fatigue, brain fog, unrefreshed sleep, and word-finding difficulties were very common and often severe. Importantly, these symptoms appeared to be caused by the virus itself rather than by pre-existing health conditions or how sick people were during acute infection.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

The Diagnostic Journey of Dysautonomia Patients: Insights from a Patient-Reported Outcome Study.

O'Dell, John A, Walker, Ash, Latham, Andrew J et al.·Journal of patient experience·2025

This study followed 672 adults with dysautonomia (a condition where the nervous system that controls automatic body functions doesn't work properly) to understand how long it takes to get diagnosed and which doctors help with diagnosis. On average, it took 7.7 years for people to receive a diagnosis, and they often saw multiple types of doctors before getting answers. The study found that dysautonomia commonly occurs alongside other conditions like Ehlers-Danlos syndrome, mast cell disorders, and ME/CFS, which can make diagnosis even more confusing.

Autonomic Nervous SystemDiagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

The immune checkpoint pathophysiology of depression and chronic fatigue syndrome due to preeclampsia: focus on sCD80 and sCTLA-4.

Omar, Jangir Sami, Albarzinji, Niaz, Niu, Mengqi et al.·Acta neuropsychiatrica·2025

This study looked at immune system markers in pregnant women with preeclampsia (a serious pregnancy condition) who also experienced depression, anxiety, and fatigue. Researchers found that certain immune molecules called sCTLA-4 and sCD80, along with imbalances in minerals like zinc and magnesium, were associated with these neuropsychiatric symptoms. The study suggests that immune system activation may play a role in why preeclampsia causes mood and fatigue problems.

Immune System

E2 ModerateCohortPEM unclearCross-Sectional

A Multidimensional Assessment of Sleep Disorders in Long COVID Using the Alliance Sleep Questionnaire.

Wilson, Alina, Ricciardiello Mejia, Giorgio Camillo, Lomba, Sara et al.·Healthcare (Basel, Switzerland)·2025

This study looked at sleep problems in 200 people with Long COVID seen at Stanford's clinic. Researchers found that more than half had breathing-related sleep issues, about 4 in 10 had insomnia, and about 3 in 10 had excessive daytime sleepiness. The study identified two different groups of patients: one with more severe sleep and systemic symptoms than the other.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCase-Control

People with Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Exhibit Similarly Impaired Vascular Function.

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

This study measured how well blood vessels work in people with long COVID and ME/CFS compared to healthy people. Researchers found that both long COVID and ME/CFS patients have similar problems with blood vessel function, even though ME/CFS patients have been sick much longer. These findings suggest that blood vessel problems may be an important part of how these illnesses develop.

E2 ModerateCohortPEM not requiredObservational

Does Prenatal SARS-CoV-2 Infection Exacerbate Postpartum Lower Urinary Tract Symptoms? A Multicenter Retrospective Cohort Study.

Lyu, Yu Han, Li, Min, Yao, Hui Qing et al.·Biomedical and environmental sciences : BES·2025

This study examined whether pregnant people who had COVID-19 experienced more urinary symptoms (like leakage or urgency) after giving birth compared to those who didn't have COVID-19. Researchers surveyed 3,652 women at two hospitals in China and found that COVID-19 infection during pregnancy did not increase reported urinary problems. However, they did find that the muscles controlling urination showed different electrical activity in women who had COVID-19, suggesting the virus may affect how these muscles work at a deeper level.

E2 ModerateCohortPEM not requiredObservational

Single-Center Study of Therapeutic Apheresis in 24 Male Patients from the MENA Region: Reduction of Lipids, Inflammatory Markers, Autoantibodies, and Implications for Fatigue, Genetics, and Aging.

Steenblock, Charlotte, Walther, Romy, Kok, Yannick et al.·Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme·2025

This study tested a blood-cleaning procedure called apheresis in 24 men from the Middle East and North Africa who had chronic fatigue and metabolic problems like diabetes or high cholesterol. The procedure removed harmful fats and immune molecules from their blood. After treatment, patients showed improvements in their blood work, with reduced inflammatory markers and autoantibodies that may contribute to fatigue.

Immune System

E2 ModerateCohortPEM not requiredCross-Sectional

Adverse effects of obesity on overall health, quality of life, and related physical health metrics: A cross-sectional and longitudinal study from the All of Us Research Program.

Yao, Zhiqi, Tchang, Beverly G, Chae, Kacey et al.·Journal of internal medicine·2025

This study looked at over 323,000 people in the United States to understand how obesity affects overall health and quality of life. Researchers found that people with higher body weight reported worse health, more pain, more fatigue, and greater difficulty with physical activity compared to people of normal weight. The effects were strongest in people with the most severe obesity, who were nearly 4 times more likely to report poor health and severe pain.

Pain and SensitizationSleep

E2 ModerateDiagnosticPEM unclearMethods-Paper

Design and validation of an energy level diary for fatigue management in patients with post-COVID syndrome.

Balke, Maryam, Garbsch, René, Cormann, Jessica et al.·Frontiers in rehabilitation sciences·2025

Researchers developed a simple daily diary to help post-COVID patients track their energy levels throughout the day. The diary showed that patients had more energy in the morning than evening, and that rest helped restore energy while active therapy temporarily reduced it. Most patients found the diary helpful for understanding how their body responds to different activities and for learning to pace themselves better.

E2 ModerateCohortPEM not requiredLongitudinal

Tracking Persistent Symptoms in Scotland (TraPSS): a longitudinal prospective cohort study of COVID-19 recovery after mild acute infection.

Sculthorpe, Nicholas F, McLaughlin, Marie, Cerexhe, Luke et al.·BMJ open·2025

This study followed 287 people in Scotland for 9 months after they had mild COVID-19 to track how long symptoms lasted. By month 9, only 3.1% still had ongoing symptoms matching Long-COVID criteria. Fatigue was the symptom that lasted longest, while cough improved quickly. The study found that older people were more likely to report pain and thinking problems, and women were more likely to experience headaches and post-exertional malaise (feeling worse after activity).

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Cognitive functioning in patients with chronic fatigue syndrome: Slowed information processing or a deficit in attentional selectivity?

Banovic, Ingrid, Šaban, Iva, Ayad, Adel et al.·Neuropsychology·2025

This study tested whether people with ME/CFS have trouble focusing their attention or simply process information more slowly. Researchers gave 83 ME/CFS patients and 83 healthy people a simple attention test (the Stroop task) where they had to name colors while ignoring conflicting words. The results showed that ME/CFS patients were slower overall, but their difficulty wasn't due to problems with attention—it was purely because their brains processed information more slowly.

Cognitive Impairment

E2 ModerateCohortPEM unclearCross-Sectional

Babesia and Bartonella Species DNA in Blood and Enrichment Blood Cultures from People with Chronic Fatigue and Concurrent Neurological Symptoms.

Breitschwerdt, Edward B, Maggi, Ricardo G, Bush, Janice C et al.·Pathogens (Basel, Switzerland)·2025

This study looked for two types of bacteria—Babesia and Bartonella—in the blood of 50 people with ME/CFS and neurological symptoms. Researchers used special DNA tests to detect these bacteria. They found that about 24% of participants had Babesia infection and 26% had Bartonella infection, suggesting these bacteria might play a role in some ME/CFS cases.

E2 ModerateCohortPEM unclearCross-Sectional

Putting the PASC Score to the Test: Clinical vs. Statistical Accuracy in Long COVID Diagnosis.

Azola, Alba, Dastgheyb, Raha M, Easter, Rebecca et al.·Journal of general internal medicine·2025

Researchers tested a scoring tool called the PASC score to see if it could correctly identify long COVID patients. They compared 130 long COVID patients with 60 people who recovered completely from COVID-19. The PASC score was very accurate at confirming who had long COVID, but missed about 20% of actual patients. A simpler approach using just three symptoms (loss of smell/taste, post-exertional malaise, or sexual dysfunction) worked even better at catching long COVID cases.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

The Physical and Mental Health of Post-9/11 Female and Male Veterans: Findings from the Comparative Health Assessment Interview Research Study.

Dursa, Erin K, Cypel, Yasmin S, Culpepper, William J et al.·Journal of women's health (2002)·2025

This study surveyed thousands of veterans from recent U.S. military operations to compare the health problems experienced by female and male veterans. Female veterans reported chronic fatigue syndrome, along with several other conditions like arthritis, migraine, and depression, at higher rates than male veterans. The findings show that both female and male veterans who had deployed experienced more health problems overall compared to non-veterans.

E2 ModerateCohortPEM not requiredCross-Sectional

Comprehensive Assessment of Autonomic Nervous System Profiles in Postural Orthostatic Tachycardia Syndrome Among Syncope, Chronic Fatigue, and Post-COVID-19 Patients.

Milovanovic, Branislav, Markovic, Nikola, Petrovic, Masa et al.·Diagnostics (Basel, Switzerland)·2025

This study examined how the nervous system functions differently in people with POTS (a condition causing rapid heart rate when standing) who also have fainting episodes, ME/CFS, or post-COVID illness. Researchers used heart rate monitors, tilt tests, and breathing exercises to measure how well the autonomic nervous system—which controls heart rate and blood pressure—works in each group. They found that POTS appears differently depending on what condition causes it: in syncope patients it involves sympathetic overdrive, while in ME/CFS patients it involves parasympathetic weakness.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredCross-Sectional

Unmasking the Long-Term Effects of COVID-19 With a Focus on Chronic Fatigue Syndrome: A Community-Based Study From India.

Gupta, Arti, Rajan, Vishnu, Aravindakshan, Rajeev et al.·Cureus·2025

This study looked at 500 COVID-19 survivors in rural India to see how many developed chronic fatigue syndrome (CFS)—a condition causing severe, lasting tiredness and other symptoms. About 21% of the COVID-19 survivors developed CFS, with older people, women, and those with existing health conditions at higher risk. The study found that fatigue, joint pain, and muscle pain were common problems after COVID-19.

Long COVID Overlap

E2 ModerateCohortPEM not requiredCross-Sectional

Brain Fog in Gastrointestinal Disorders: Small Intestinal Bacterial Overgrowth, Gastroparesis, Irritable Bowel Syndrome.

El Halabi, Maan, Arwani, Remy, Rao, Satish C et al.·Journal of clinical gastroenterology·2025

This study looked at brain fog—difficulty concentrating, remembering things, and thinking clearly—in patients with common digestive problems. Researchers surveyed 102 patients undergoing breath tests for bacterial overgrowth and found that over half reported brain fog. Those taking probiotics or with gastroparesis (slow stomach emptying) or irritable bowel syndrome were more likely to have brain fog.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Cardio-Respiratory Fitness and Fatigue in Post-COVID-19 Syndrome-A Three-Year Update.

Cherneva, Radostina, Cherneva, Zheyna, Youroukova, Vania et al.·Biomedicines·2025

More than two years after COVID-19 infection, about a quarter of people still experience persistent symptoms including fatigue, breathing problems, and reduced ability to exercise. Researchers tested how well patients' hearts and lungs worked during exercise and found that those with moderate-to-severe symptoms had noticeably reduced fitness levels and felt more exhausted even when not working as hard as their test results showed they should be.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Medical complexity and healthcare utilization among patients attending three U.S. post-COVID clinics.

Nji, Miriam A M, Briones, Elizabeth M, Issa, Anindita et al.·BMC infectious diseases·2025

This study looked at 984 patients who visited specialized clinics for ongoing problems after COVID-19 infection. Patients commonly experienced shortness of breath, fatigue, post-exertional malaise (feeling much worse after activity), and brain fog. Most patients needed multiple medical visits and referrals to different specialists like lung, heart, and neurologists, showing that post-COVID illness is complex and requires coordinated care from many healthcare providers.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Cross-Sectional Study Evaluating the Role of Autonomic Nervous System Functional Diagnostics in Differentiating Post-Infectious Syndromes: Post-COVID Syndrome, Chronic Fatigue Syndrome, and Lyme Disease.

Milovanovic, Branislav, Markovic, Nikola, Petrovic, Masa et al.·Biomedicines·2025

This study compared how the nervous system functions differently in people with Post-COVID syndrome, ME/CFS (both COVID-related and unrelated), and late-stage Lyme disease—three conditions that often feel similar but may have different causes. Researchers tested 758 patients using heart rhythm monitors, tilt tests, and blood pressure measurements to see how their bodies responded to position changes and stress. They found that Lyme disease patients showed a distinct pattern of nerve dysfunction (adrenergic failure), while Post-COVID and ME/CFS patients had different types of nervous system imbalances.

Autonomic Nervous System

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Prevalence and severity of neurologic symptoms in Long-COVID and the role of pre-existing conditions, hospitalization, and mental health.

The Diagnostic Journey of Dysautonomia Patients: Insights from a Patient-Reported Outcome Study.

The immune checkpoint pathophysiology of depression and chronic fatigue syndrome due to preeclampsia: focus on sCD80 and sCTLA-4.

A Multidimensional Assessment of Sleep Disorders in Long COVID Using the Alliance Sleep Questionnaire.

People with Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Exhibit Similarly Impaired Vascular Function.

Does Prenatal SARS-CoV-2 Infection Exacerbate Postpartum Lower Urinary Tract Symptoms? A Multicenter Retrospective Cohort Study.

Single-Center Study of Therapeutic Apheresis in 24 Male Patients from the MENA Region: Reduction of Lipids, Inflammatory Markers, Autoantibodies, and Implications for Fatigue, Genetics, and Aging.

Adverse effects of obesity on overall health, quality of life, and related physical health metrics: A cross-sectional and longitudinal study from the All of Us Research Program.

Design and validation of an energy level diary for fatigue management in patients with post-COVID syndrome.

Tracking Persistent Symptoms in Scotland (TraPSS): a longitudinal prospective cohort study of COVID-19 recovery after mild acute infection.

Cognitive functioning in patients with chronic fatigue syndrome: Slowed information processing or a deficit in attentional selectivity?

Babesia and Bartonella Species DNA in Blood and Enrichment Blood Cultures from People with Chronic Fatigue and Concurrent Neurological Symptoms.

Putting the PASC Score to the Test: Clinical vs. Statistical Accuracy in Long COVID Diagnosis.

The Physical and Mental Health of Post-9/11 Female and Male Veterans: Findings from the Comparative Health Assessment Interview Research Study.

Comprehensive Assessment of Autonomic Nervous System Profiles in Postural Orthostatic Tachycardia Syndrome Among Syncope, Chronic Fatigue, and Post-COVID-19 Patients.

Unmasking the Long-Term Effects of COVID-19 With a Focus on Chronic Fatigue Syndrome: A Community-Based Study From India.

Brain Fog in Gastrointestinal Disorders: Small Intestinal Bacterial Overgrowth, Gastroparesis, Irritable Bowel Syndrome.

Cardio-Respiratory Fitness and Fatigue in Post-COVID-19 Syndrome-A Three-Year Update.

Medical complexity and healthcare utilization among patients attending three U.S. post-COVID clinics.

Cross-Sectional Study Evaluating the Role of Autonomic Nervous System Functional Diagnostics in Differentiating Post-Infectious Syndromes: Post-COVID Syndrome, Chronic Fatigue Syndrome, and Lyme Disease.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research