Search and filter 6,209 studies by evidence level, diagnostic criteria, PEM status, and research domain. Each entry links to the original source.
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Evidence level (E0–E3) reflects study type and replication, not methodological quality. A weak systematic review still sits at E0. How evidence levels work →
4401–4420 of 6,209 studies
BMJ paediatrics open·2021
This article is a personal account of one person's experience living with ME/CFS, published in a medical journal. It describes the journey of managing this condition and how it has affected daily life. While personal stories are valuable for understanding what patients go through, they are not the same as research that tests treatments or identifies causes.
Maes, Michael, Kubera, Marta, Stoyanova, Kristina et al.·Current topics in medicinal chemistry·2021
This study found that ME/CFS involves measurable problems with the immune system and cellular stress rather than being primarily psychological. Researchers identified specific markers in the blood—including signs of bacterial leak from the gut, immune cell activation, and oxidative damage—that together explained about one-third of ME/CFS symptoms. Importantly, the study identified three distinct subgroups of ME/CFS patients with different immune patterns, suggesting the condition may not be the same in everyone.
Maggini, Silvia, Óvári, Veronika, Ferreres Giménez, Inmaculada et al.·Nutricion hospitalaria·2021
Your body needs several vitamins and minerals—like vitamins A, D, E, folate, iron, zinc, and selenium—to make energy in your cells. Many people, even in wealthy countries, don't get enough of these nutrients. Studies show that taking a combination of these micronutrients, sometimes with coenzyme Q10, may help reduce fatigue, improve thinking, and make people feel better overall.
Oleksak, Filip, Durdik, Peter, Jakusova, Lubica et al.·Advances in respiratory medicine·2021
This case report describes a young patient who was diagnosed with ME/CFS (extreme exhaustion lasting at least six months) but actually had a different, treatable heart and lung condition. The doctors used a special exercise test called cardiopulmonary exercise testing to discover the real cause. This story reminds us that it's important to carefully check for other medical conditions before diagnosing someone with ME/CFS, especially in children and young people.
Lidbury, Brett A·Frontiers in medicine·2021
This study examines how Ross River virus, a mosquito-borne virus common in Australia, might trigger long-lasting fatigue and ME/CFS symptoms. The virus uses several tricks to hide from the immune system, and researchers propose these tricks may disrupt the body's energy-producing systems and cause the persistent exhaustion seen in ME/CFS. The findings suggest that understanding how this virus evades immunity could help explain why some viral infections lead to chronic fatigue.
Maugars, Yves, Berthelot, Jean-Marie, Le Goff, Benoit et al.·Frontiers in medicine·2021
This article reviews what scientists know about fibromyalgia as of 2020, including how it's diagnosed and why it happens. The authors explain that fibromyalgia involves the brain processing pain signals too intensely, and that people with fibromyalgia often experience many other symptoms like fatigue, sleep problems, and sensitivity to sounds, lights, and touch. They also discuss how fibromyalgia shares common features with other conditions like ME/CFS, all involving a heightened sensitivity to stimuli controlled by the central nervous system.
Tang, Qianqian, Cao, Lihua·Sheng wu gong cheng xue bao = Chinese journal of biotechnology·2021
Your gut bacteria (microbiome) communicate with your brain through multiple pathways, including immune signals and nerve connections. When this gut-brain communication goes wrong, it may contribute to various neurological conditions, including chronic fatigue syndrome. This review summarizes what scientists know about how imbalanced gut bacteria might affect the nervous system and cause disease.
Cheshire, Anna, Ridge, Damien, Clark, Lucy V et al.·Qualitative health research·2021
This study asked 19 people with ME/CFS what "recovery" means to them—some had improved and some had gotten worse after trying a self-help treatment. The researchers found that recovery doesn't mean the same thing to everyone. While some people wanted to be completely symptom-free, many others just wanted to feel "normal" again and stop being defined by their illness, even if symptoms remained. Some people actually didn't want to return to their old lifestyle, thinking it might have caused their illness in the first place.
Klaver-Krol, E G, Hermens, H J, Vermeulen, R C et al.·Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology·2021
Researchers used muscle sensors to measure how electrical signals travel through muscle fibers in people with ME/CFS, fibromyalgia, and healthy people during light strength exercises. They found that in ME/CFS patients, these electrical signals traveled unusually fast through muscle fibers as force increased, which didn't happen in the other groups. This suggests that muscle cells in ME/CFS may have a problem with how they work at the membrane level.
Yong, Shin Jie·ACS chemical neuroscience·2021
This paper suggests that long-COVID symptoms may be caused by damage to the brainstem, a part of the brain that controls basic functions like breathing, heart rate, and digestion. The authors propose that the coronavirus may directly infect the brainstem or cause inflammation there, and because brain cells heal slowly, this damage could persist long after the initial infection. This theory could help explain why long-COVID patients experience lasting fatigue, breathing problems, and other widespread symptoms.
Wirth, Klaus J, Scheibenbogen, Carmen·Journal of translational medicine·2021
This study proposes that ME/CFS may be caused by a problem with how the body's nervous system controls blood vessels and muscle function. The researchers suggest that faulty beta-2 receptors (proteins that normally help regulate these systems) lead to poor blood flow in muscles, buildup of harmful substances, and damage to the energy-producing structures inside muscle cells. This creates a harmful cycle where even small amounts of activity can trigger the same problems again and again, explaining why patients experience crashes after exertion.
Weir, William, Speight, Nigel·Healthcare (Basel, Switzerland)·2021
This article reviews the history and current understanding of ME/CFS, arguing that the condition has a biological basis rather than being primarily psychological. The authors emphasize that scientific research, not psychological theories, is the path forward for properly understanding and treating ME/CFS. They highlight how patients have suffered from misunderstandings about their condition's cause.
Carod-Artal, F J·Revista de neurologia·2021
Many people who have had COVID-19, even mild cases, don't fully recover and experience long-lasting symptoms for months afterward. This article reviews what we know about post-COVID-19 syndrome, including who gets it, what symptoms they have, and what might be causing it. Common symptoms include fatigue, breathing problems, difficulty concentrating, anxiety, and depression. The exact biological reasons why this happens are still unknown, though experts think abnormal immune and inflammatory responses may play a role.
Yang, Xingzhe, Li, Feng, Ma, Jie et al.·Journal of molecular neuroscience : MN·2021
This review examines how tiny molecules called miRNAs (and related molecules like lncRNAs and circRNAs) may control genes involved in fatigue. These molecules work together in a network to influence energy production, immune function, and brain signaling—all key factors in chronic fatigue. The authors argue that understanding this genetic control network could help explain why people develop fatigue and potentially lead to better ways to diagnose and treat it.
Shiha, Mohamed G, Aziz, Imran·Alimentary pharmacology & therapeutics·2021
This review examines how irritable bowel syndrome (IBS) commonly occurs alongside other physical and mental health conditions, particularly chronic fatigue syndrome, fibromyalgia, anxiety, and depression. Patients with IBS often experience symptoms beyond the digestive system that significantly impact their quality of life and healthcare costs. The authors discuss why these conditions cluster together and suggest better ways to manage patients who have multiple conditions at once.
Petracek, Lindsay S, Suskauer, Stacy J, Vickers, Rebecca F et al.·Frontiers in medicine·2021
This study describes three teenagers and young adults who developed ME/CFS after having COVID-19. All three patients experienced symptoms like dizziness when standing up early in their illness, and by 6 months, all met the clinical criteria for ME/CFS. The researchers noticed several patterns across these patients, including allergies, elevated histamine levels, reduced flexibility, and unusual nerve reflexes—findings that may help identify and treat ME/CFS after COVID-19.
Ahn, Yo-Chan, Lee, Jin-Seok, Son, Chang-Gue·Healthcare (Basel, Switzerland)·2020
This study tested whether a Korean version of a fatigue measurement tool called the mKCFQ11 accurately measures fatigue in ME/CFS patients. Researchers gave the test to 97 people and compared their scores to other well-known fatigue and quality-of-life tests. The tool performed very well, reliably measuring both physical and mental fatigue.
Wang, Xin, Wu, Min, Lai, Xinxing et al.·Oxidative medicine and cellular longevity·2020
This study used computer analysis and lab experiments to understand how traditional Chinese medicine views a condition called "spleen qi deficiency," which is linked to various diseases including chronic fatigue. Researchers found that this condition may involve problems with the immune system and how the body handles stress at the cellular level. They also identified which herbs traditionally used for this condition work by boosting immune cell activity.
Lee, Jin-Seok, Jeon, Yoo-Jin, Park, Samuel-Young et al.·Biomolecules·2020
Researchers tested three different mouse models to find the best one for studying ME/CFS. They found that removing the adrenal glands (small organs that produce stress hormones) in mice created fatigue and pain symptoms most similar to ME/CFS, while other common models mainly produced depression-like behaviors. The adrenal-removed mice also showed specific brain changes involving inflammation and stress hormone pathways.
Polli, Andrea, Ghosh, Manosij, Bakusic, Jelena et al.·Arthritis & rheumatology (Hoboken, N.J.)·2020
This study found that people with ME/CFS and fibromyalgia have unusual patterns in how their genes are regulated, specifically involving a molecule called BDNF that affects pain and nerve function. Researchers measured genetic markers and protein levels in blood samples and found that changes in how BDNF genes are 'switched on and off' may explain why patients experience severe fatigue, pain, and widespread body aches.
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Thematic groupings by clinical question or research area.
PET imaging and other studies providing evidence for brain inflammation in ME/CFS.
NeurologyMetabolomics and mitochondrial function studies revealing energy metabolism disruption.
MetabolismStudies identifying potential biological markers for ME/CFS diagnosis and stratification.
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