ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

1241–1260 of 6,209 studies

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

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

Long-Term Impairment of Working Ability in Subjects under 60 Years of Age Hospitalised for COVID-19 at 2 Years of Follow-Up: A Cross-Sectional Study.

Frallonardo, Luisa, Ritacco, Annunziata Ilenia, Amendolara, Angela et al.·Viruses·2024

This study followed 322 people under age 60 who were hospitalized with COVID-19 and checked on them about 2 years later. Researchers found that 42% of these patients reported difficulty working compared to before they got sick, even though they had recovered from the acute infection. The study identified that women, people with diabetes, and those who needed oxygen during hospitalization were more likely to have lasting work problems.

Long COVID Overlap

E2 ModerateCohortPEM unclearCross-Sectional

Exploring levels of TSH and FT4 in patients with chronic fatigue syndrome (CFS), fibromyalgia (FM) and healthy controls did not reveal any associations between fatigue score and level of thyroid hormones.

Skorpen, Elias, Pasca, Nora Bugge, Reitan, Solveig Klæbo et al.·Nordic journal of psychiatry·2024

Researchers compared thyroid hormone levels in women with ME/CFS, women with fibromyalgia, and healthy women to see if thyroid function might explain fatigue. They found no differences in thyroid hormone levels between the groups and no connection between how tired someone felt and their thyroid hormone levels.

E2 ModerateMechanismPEM not requiredMechanistic

Manual Therapy Improves Fibromyalgia Symptoms by Downregulating SIK1.

Bonastre-Férez, Javier, Giménez-Orenga, Karen, Falaguera-Vera, Francisco Javier et al.·International journal of molecular sciences·2024

This study tested whether a specialized hands-on therapy treatment could help fibromyalgia patients and discovered why it might work. Researchers found that the treatment lowered levels of a specific gene called SIK1 in patients' blood cells, and this change was linked to improvements in pain, fatigue, and quality of life. Importantly, this gene change only happened in fibromyalgia patients who received the treatment—not in healthy people who got the same therapy.

Biomarkers

E2 ModerateCohortPEM unclearLongitudinal

Long-term COVID-19 sequelae by Theta and SARS-CoV-2 variants in a Philippine cohort.

Saloma, Cynthia P, Ayes, Marc Edsel C, Taracatac, Paolo S et al.·Frontiers in medicine·2024

This study followed people in the Philippines who had COVID-19 to see how long their symptoms lasted and whether different COVID variants caused different long-term problems. Researchers checked in with patients three times over a year and found that most people (68-88%) still had symptoms months after infection, with fatigue, brain fog, and headaches being the most common. The good news was that symptoms generally improved over time, though many people continued to struggle with debilitating effects.

Post-Exertional Malaise

E2 ModerateBehavioralPEM not requiredObservational

Clinical outcomes, medical costs, and medication usage patterns of different somatic symptom disorders and functional somatic syndromes: a population-based study in Taiwan.

Wu, Chi-Shin, Chen, Tzu-Ting, Liao, Shih-Cheng et al.·Psychological medicine·2024

This study compared people diagnosed with somatic symptom disorder and four types of functional somatic syndromes (including ME/CFS) to matched healthy controls in Taiwan. Patients with these conditions had higher rates of psychiatric hospitalization, suicide, death, and healthcare costs than controls, and used psychiatric medications and pain relievers more often. Overall, these conditions showed similar patterns of serious health outcomes and expenses.

E2 ModerateCohortPEM unclearLongitudinal

Three-Month Follow-Up of the Post-COVID Syndrome after Admission to a Specialised Post-COVID Centre-A Prospective Study Focusing on Mental Health with Patient Reported Outcome Measures (PROMs).

Schäfer, Isabel Cecil, Krehbiel, Johannes, Adler, Werner et al.·International journal of environmental research and public health·2024

Researchers followed 265 Post-COVID patients for about 5 months to understand how mental health symptoms changed over time. They found that most patients still had severe Post-COVID symptoms, with nearly 9 in 10 reporting extreme fatigue and about half experiencing depression. Importantly, while depression and anxiety improved somewhat over time, fatigue and post-exertional malaise (getting worse after activity) stayed at very high levels and did not improve.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredLongitudinal

Exploring the prevalence and chest CT predictors of Long COVID in children: a comprehensive study from Shanghai and Linyi.

Yin, Yong, Yang, Guijun, Wang, Na et al.·Frontiers in pediatrics·2024

This study looked at 416 children who had COVID-19 and received chest CT scans. About 23% of the children who were followed up developed Long COVID—experiencing symptoms like lasting cough, tiredness, brain fog, and worsening after physical activity. The researchers found that children with certain patterns on their chest CT scans (increased blood vessel markings) and younger children were more likely to develop Long COVID.

E2 ModerateMechanismPEM unclearMechanistic

Data-independent LC-MS/MS analysis of ME/CFS plasma reveals a dysregulated coagulation system, endothelial dysfunction, downregulation of complement machinery.

Nunes, Massimo, Vlok, Mare, Proal, Amy et al.·Cardiovascular diabetology·2024

Researchers analyzed blood proteins in 15 ME/CFS patients and 10 healthy controls to look for differences that might explain ME/CFS symptoms. They found that ME/CFS patients had abnormal levels of proteins involved in blood clotting, blood vessel function, and immune system regulation. These findings suggest that problems with blood clotting and blood vessel health may play a role in ME/CFS.

BiomarkersImmune System

E2 ModerateCohortPEM not requiredCross-Sectional

Presence of endometriosis and chronic overlapping pain conditions negatively impacts the pain experience in women with chronic pelvic-abdominal pain: A cross-sectional survey.

Bartley, Emily J, Alappattu, Meryl J, Manko, Kelsey et al.·Women's health (London, England)·2024

This study looked at 525 women with chronic pelvic and abdominal pain to understand how endometriosis (a condition where tissue grows outside the uterus) affects their pain experience. Women with endometriosis reported more severe pain, greater interference with daily life, and were more likely to have other overlapping pain conditions like fibromyalgia and chronic fatigue syndrome. The more pain conditions a woman had, the worse her overall pain burden became, regardless of whether she had endometriosis.

Pain and Sensitization

E2 ModerateCohortPEM unclearObservational

Sleep and circadian rhythm alterations in myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID fatigue syndrome and its association with cardiovascular risk factors: A prospective cohort study.

Zerón-Rugerio, María Fernanda, Zaragozá, Maria Cleofé, Domingo, Joan Carles et al.·Chronobiology international·2024

This study looked at sleep patterns and daily body rhythms in ME/CFS patients and compared them to healthy people. Researchers found that ME/CFS patients had lower activity levels, worse sleep quality, and unhealthy cholesterol levels compared to healthy controls. The study also found that problems with blood vessel function may connect sleep disruptions to heart health problems in ME/CFS patients.

Long COVID Overlap

E2 ModerateCohortPEM not required

Joint Flexibility and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After Mononucleosis.

Poomkudy, Jeffrey Thomas, Torres, Chelsea, Jason, Leonard A et al.·Clinical therapeutics·2024

This study looked at whether having unusually flexible joints might increase the risk of developing ME/CFS after a mono infection. Researchers followed college students who got mono and checked 6 months later who had developed ME/CFS. They measured joint flexibility using a standard test and compared the flexibility of those who developed ME/CFS with those who recovered normally. The study found no connection between joint flexibility and developing ME/CFS after mono.

E2 ModerateBehavioralPEM not requiredLongitudinal

All-or-Nothing Behavior and Catastrophic Thinking Predict Fatigue in Inflammatory Bowel Disease: A Prospective Cohort Study.

Moulton, Calum D, Jordan, Cheryl, Hayee, Bu'Hussain et al.·Inflammatory bowel diseases·2024

This study looked at people with inflammatory bowel disease (IBD) who experience fatigue and found that two behavior patterns predict worsening tiredness over time: all-or-nothing behavior (doing a lot of activity followed by needing extended rest) and catastrophic thinking (expecting the worst outcomes). These findings suggest that how patients think and behave may play an important role in their fatigue levels.

E2 ModerateCohortPEM not requiredCase-Control

[Association of inflammation and chronic fatigue syndrome in patients with Parkinson's disease].

Nikitina, M A, Bragina, E Yu, Ivanova, S A et al.·Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova·2024

This study looked at severe tiredness (chronic fatigue syndrome) in people with Parkinson's disease. Researchers found that about two-thirds of Parkinson's patients experience this kind of fatigue, and it tends to occur alongside other symptoms like mood problems, memory difficulties, and pain. Blood tests showed that people with this fatigue had higher levels of inflammation markers, suggesting that inflammation may play a role in causing the tiredness.

Neuroinflammation

E2 ModerateMechanismPEM unclearMechanistic

Phenylephrine alters phase synchronization between cerebral blood velocity and blood pressure in ME/CFS with orthostatic intolerance.

Medow, Marvin S, Stewart, Julian M·American journal of physiology. Regulatory, integrative and comparative physiology·2024

People with ME/CFS often experience brain fog and cognitive problems when standing up, possibly because their brain isn't getting enough blood flow and oxygen. This study tested whether a medication called phenylephrine could help restore brain blood flow and improve thinking during standing. The researchers found that phenylephrine was the only treatment tested that significantly improved both cognitive performance and the brain's ability to maintain stable blood flow during head-up tilting.

Autonomic Nervous SystemCognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Validity and diagnostic overlap of functional somatic syndrome diagnoses.

van der Meulen, Monica L, Bos, Martje, Bakker, Stephan J L et al.·Journal of psychosomatic research·2024

This study looked at how often three common conditions—ME/CFS, fibromyalgia, and irritable bowel syndrome—occur together in the general population. Researchers surveyed nearly 90,000 people and found that these conditions overlap far more often than would happen by pure chance, especially when they last longer and cause more serious symptoms. This suggests these conditions may share common underlying features.

Diagnostics

E2 ModerateBehavioralPEM unclearObservational

Outpatient group therapy for post-COVID patients - a naturalistic feasibility study of a face-to-face and online group concept.

Zimmermann-Schlegel, Verena, Gronewold, Nadine, Stengel, Sandra et al.·Frontiers in psychiatry·2024

Researchers created and tested a group therapy program for people with Post-COVID syndrome that meets weekly for 8 sessions to help manage fatigue, stress sensitivity, and other symptoms. The program was offered both in-person and online to 57 patients, and most participants found it helpful, especially valuing the chance to connect with others experiencing similar challenges. The results suggest this type of group therapy is safe and acceptable, with the online format being particularly useful for people who have difficulty leaving home.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Reactivation of herpesvirus type 6 and IgA/IgM-mediated responses to activin-A underpin long COVID, including affective symptoms and chronic fatigue syndrome.

Vojdani, Aristo, Almulla, Abbas F, Zhou, Bo et al.·Acta neuropsychiatrica·2024

This study found that long COVID patients have higher levels of antibodies (immune proteins) against reactivated dormant viruses, particularly herpesvirus type 6, along with signs of ongoing inflammation and immune activation. The researchers identified a pattern of immune markers that correctly identified long COVID patients about 81% of the time, and similar patterns were linked to depression, anxiety, and fatigue symptoms. These findings suggest that viral reactivation combined with abnormal immune responses may drive long COVID and its associated mood and fatigue symptoms.

Immune System

E2 ModerateCohortPEM not requiredCross-Sectional

Plasma and peritoneal fluid cytokine profiles in patient with Essure® implant: Towards a molecular signature?

Garnier, Lorna, Parant, François, Bulteau, Claire et al.·European journal of obstetrics, gynecology, and reproductive biology·2024

Researchers measured inflammation markers (cytokines) in blood and fluid from the abdomen in women with Essure implants, women with endometriosis, and healthy controls. They found that women with Essure implants had higher levels of two specific inflammation markers (MCP-1 and TNF-α) in their blood compared to controls. These same markers are known to be elevated in fibromyalgia and chronic fatigue syndrome, suggesting they might be relevant to understanding Essure-related symptoms.

Immune System

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

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

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

Long-Term Impairment of Working Ability in Subjects under 60 Years of Age Hospitalised for COVID-19 at 2 Years of Follow-Up: A Cross-Sectional Study.

Exploring levels of TSH and FT4 in patients with chronic fatigue syndrome (CFS), fibromyalgia (FM) and healthy controls did not reveal any associations between fatigue score and level of thyroid hormones.

Manual Therapy Improves Fibromyalgia Symptoms by Downregulating SIK1.

Long-term COVID-19 sequelae by Theta and SARS-CoV-2 variants in a Philippine cohort.

Clinical outcomes, medical costs, and medication usage patterns of different somatic symptom disorders and functional somatic syndromes: a population-based study in Taiwan.

Three-Month Follow-Up of the Post-COVID Syndrome after Admission to a Specialised Post-COVID Centre-A Prospective Study Focusing on Mental Health with Patient Reported Outcome Measures (PROMs).

Exploring the prevalence and chest CT predictors of Long COVID in children: a comprehensive study from Shanghai and Linyi.

Data-independent LC-MS/MS analysis of ME/CFS plasma reveals a dysregulated coagulation system, endothelial dysfunction, downregulation of complement machinery.

Presence of endometriosis and chronic overlapping pain conditions negatively impacts the pain experience in women with chronic pelvic-abdominal pain: A cross-sectional survey.

Sleep and circadian rhythm alterations in myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID fatigue syndrome and its association with cardiovascular risk factors: A prospective cohort study.

Joint Flexibility and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After Mononucleosis.

All-or-Nothing Behavior and Catastrophic Thinking Predict Fatigue in Inflammatory Bowel Disease: A Prospective Cohort Study.

[Association of inflammation and chronic fatigue syndrome in patients with Parkinson's disease].

Phenylephrine alters phase synchronization between cerebral blood velocity and blood pressure in ME/CFS with orthostatic intolerance.

Validity and diagnostic overlap of functional somatic syndrome diagnoses.

Outpatient group therapy for post-COVID patients - a naturalistic feasibility study of a face-to-face and online group concept.

Reactivation of herpesvirus type 6 and IgA/IgM-mediated responses to activin-A underpin long COVID, including affective symptoms and chronic fatigue syndrome.

Plasma and peritoneal fluid cytokine profiles in patient with Essure® implant: Towards a molecular signature?

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research