Evidence browser

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 SensitizationSleepCognitive Impairment

Identifying commonalities and differences between EHR representations of PASC and ME/CFS in the RECOVER EHR cohort.

Powers, John P, McIntee, Tomas J, Bhatia, Abhishek et al.·Communications medicine·2025

Researchers compared medical records from millions of patients to see how Long COVID (PASC) and ME/CFS are similar and different. They found that both conditions share common symptoms like fatigue, breathing difficulties, and trouble concentrating, but Long COVID tends to have more heart and lung problems, while ME/CFS more often involves pain and sleep issues. These similarities suggest that some treatment approaches might help both conditions.

E2 ModerateCohortPEM requiredCross-Sectional

Exploratory study on autoantibodies to arginine-rich human peptides mimicking Epstein-Barr virus in women with post-COVID and myalgic encephalomyelitis/chronic fatigue syndrome.

Hoheisel, Friederike, Fleischer, Kathrin Maria, Rubarth, Kerstin et al.·Frontiers in immunology·2025

This study looked for certain antibodies in the blood of women with post-COVID and ME/CFS that might mistakenly attack the body's own proteins. The researchers found that patients with these conditions had more of these problematic antibodies than healthy people, and these antibodies were linked to common ME/CFS symptoms like fatigue, brain fog, pain, and autonomic problems. The results suggest that a virus (EBV) may trigger the immune system to attack human proteins that look similar to viral proteins.

Pain and SensitizationAutonomic Nervous SystemCognitive Impairment

E2 ModerateCohortPEM requiredCross-Sectional

The association of fatigue and pain with cognitive test performance in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Oosterman, Joukje M, van der Schaaf, Marieke, de Kleijn, Willemien P E et al.·Journal of psychosomatic research·2025

This study looked at how fatigue and pain affect thinking and memory problems in people with ME/CFS. Researchers tested 1,375 patients on tasks like reaction time and attention, and found that both fatigue severity and pain severity were linked to worse cognitive performance. The effects were stronger in older patients, suggesting that age may play a role in how much fatigue and pain impact thinking abilities.

Pain and SensitizationCognitive Impairment

Pain and SensitizationAutonomic Nervous SystemCognitive Impairment

Nonpelvic comorbid symptoms of 45 patients with pain of pelvic venous origin, before and after treatment.

Smith, Steven J, Smith, B Holly, Sichlau, Michael J et al.·Phlebology·2025

This study looked at 45 women with chronic pelvic pain caused by abnormal blood pooling in pelvic veins. These patients experienced many symptoms beyond pelvic pain—including brain fog, fatigue, migraines, constipation, and anxiety. After receiving a catheter-based procedure to fix the blood pooling, most of these systemic symptoms improved significantly (by 50% or more).

E2 ModerateCohortPEM unclearObservational

Low-dose Naltrexone Improves post-COVID-19 condition Symptoms.

Tamariz, Leonardo, Bast, Elizabeth, Klimas, Nancy et al.·Clinical therapeutics·2024

This study looked at whether treatments used for ME/CFS could help people with long COVID. Researchers reviewed records from 108 patients who tried different treatments including low-dose naltrexone, amitriptyline, duloxetine, and physical therapy. They found that patients taking low-dose naltrexone were about 5 times more likely to improve compared to those doing physical therapy alone, with improvements in both fatigue and pain.

Pain and SensitizationCognitive Impairment

E2 ModerateCohortPEM requiredCross-Sectional

Dry eye symptoms and signs in United States Gulf War era veterans with myalgic encephalomyelitis/chronic fatigue syndrome.

Sanchez, Victor, Kim, Colin K, Locatelli, Elyana V T et al.·Clinical & experimental ophthalmology·2024

Researchers studied eye dryness and discomfort in Gulf War veterans with ME/CFS and compared them to veterans without the condition. They found that people with ME/CFS reported significantly more eye pain and dryness symptoms, even though physical examination of their eyes showed similar amounts of tear production and surface damage as the control group. This suggests that the eye pain experienced by ME/CFS patients may come from causes beyond just dry eyes.

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.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Impact on Quality of Life (QoL) of Persons with ME/CFS.

Muirhead, Nina L, Vyas, Jui, Ephgrave, Rachel et al.·Medicina (Kaunas, Lithuania)·2024

This study surveyed 876 people with ME/CFS from 26 countries to understand how the condition affects their daily lives. People with ME/CFS reported very poor quality of life, with an average health rating of 36 out of 100. The most common problems were difficulty doing everyday activities (97%), pain (92%), and trouble with movement (83%).

Effect of Central Sensitization in Patients with Familial Mediterranean Fever, Axial Spondyloarthritis, and Both Diseases.

Kaya, Mehmet Nur, Kılıç, Özlem, Doğan, Abdullah et al.·Cureus·2023

This study looked at whether three groups of patients—those with familial Mediterranean fever (FMF), a type of spinal arthritis (axSpA), or both conditions—experience heightened pain sensitivity and related symptoms like fatigue and fibromyalgia compared to healthy people. Researchers used a questionnaire to measure 'central sensitization,' which is when the nervous system amplifies pain signals. They found that patients with these conditions did score higher on pain sensitivity measures than healthy controls, and chronic fatigue was particularly common in the FMF group.

E2 ModerateBehavioralPEM not requiredCross-Sectional

A comparison of pain, fatigue, and function between post-COVID-19 condition, fibromyalgia, and chronic fatigue syndrome: a survey study.

Haider, Saman, Janowski, Adam J, Lesnak, Joseph B et al.·Pain·2023

This study surveyed 707 people with post-COVID-19, fibromyalgia, and/or ME/CFS to compare their symptoms. Researchers found that all three conditions share similar patterns of pain, fatigue, brain fog, anxiety, and depression that impact daily life. People with post-COVID-19 reported somewhat less severe pain and fatigue than those with fibromyalgia or ME/CFS, but those with multiple diagnoses had worse symptoms overall.

Pain and SensitizationCognitive Impairment

E2 ModerateCohortPEM required

Brainstem volume changes in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID patients.

Thapaliya, Kiran, Marshall-Gradisnik, Sonya, Barth, Markus et al.·Frontiers in neuroscience·2023

Researchers used advanced MRI scans to examine a part of the brain called the brainstem in patients with ME/CFS and long COVID, comparing them to healthy people. They found that both patient groups had larger volumes in certain brainstem areas compared to healthy controls. The size of specific brainstem regions also correlated with symptom severity, particularly pain and breathing difficulties.

E2 ModerateCohortPEM not requiredCase-Control

The Impact of Micro RNA-320a Serum Level on Severity of Symptoms and Cerebral Processing of Pain in Patients with Fibromyalgia.

Hussein, Mona, Fathy, Wael, Abdelaleem, Enas A et al.·Pain medicine (Malden, Mass.)·2022

Researchers measured a molecule called miR-320a in the blood of people with fibromyalgia and compared it to healthy people. They found that fibromyalgia patients had higher levels of this molecule, and those with higher levels tended to have worse symptoms like pain, fatigue, sleep problems, and depression. However, this molecule did not appear to affect how the brain processes pain signals.

E2 ModerateDiagnosticPEM unclearMethods-Paper

Assessing sleep and pain among adults with myalgic encephalomyelitis/chronic fatigue syndrome: psychometric evaluation of the PROMIS® sleep and pain short forms.

Yang, Manshu, Keller, San, Lin, Jin-Mann S·Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation·2022

This study tested whether two questionnaires (PROMIS scales) accurately measure sleep problems and pain in people with ME/CFS. Researchers surveyed over 600 ME/CFS patients and 338 healthy people at seven clinics across the USA. The questionnaires worked well—they consistently measured what they were supposed to measure, and they clearly showed the difference between ME/CFS patients (who had worse sleep and pain) and healthy controls.

The incidence and characteristics of chronic pain and fatigue after 12 months later admitting with COVID-19; The Post- COVID 19 syndrome.

Janbazi, Lobaneh, Kazemian, Alireza, Mansouri, Kourosh et al.·American journal of physical medicine & rehabilitation·2022

Researchers followed 157 people who were hospitalized with COVID-19 and checked on them 12 months later. They found that about 27% still had chronic fatigue and muscle weakness, and about 15% experienced chronic pain, mostly in the lower back and legs. Women were more likely than men to report these symptoms, and many patients were only using pain medications rather than receiving rehabilitation or mental health support.

E2 ModerateCohortPEM unclearCross-Sectional

The Significance of Pain Drawing as a Screening Tool for Cervicogenic Headache and Associated Symptoms in Chronic Fatigue.

Bernhoff, Gabriella, Huhmar, Helena M, Rasmussen-Barr, Eva et al.·Journal of pain research·2022

This study looked at whether a simple drawing tool could help identify a specific type of headache (cervicogenic headache) in people with ME/CFS. Researchers found that 42% of ME/CFS patients had a particular pain pattern on their drawings that suggested their headache came from their neck. Patients with this neck-related pain pattern also experienced more dizziness, worse pain, and lower quality of life compared to others.

E2 ModerateCohortPEM unclearLongitudinal

Impact of Life Stressors on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Symptoms: An Australian Longitudinal Study.

Balinas, Cassandra, Eaton-Fitch, Natalie, Maksoud, Rebekah et al.·International journal of environmental research and public health·2021

This Australian study followed 36 ME/CFS patients over five months to see how life stressors affected their symptoms. The researchers found that major life changes like work disruptions or money problems were linked to worsening symptoms like brain fog, stomach issues, pain, and sleep problems. Interestingly, patients who had better access to healthcare and support services experienced fewer severe symptoms.

E2 ModeratePEM not requiredRegistry-Resource

Sarcoidosis among US Hispanics in a Nationwide Registry.

Innabi, Ayoub, Alzghoul, Bashar N, Kalra, Saminder et al.·Respiratory medicine·2021

This study looked at how sarcoidosis (a disease that causes inflammation in the body) affects Hispanic patients in the United States compared to non-Hispanic patients. Researchers surveyed nearly 3,835 people and found that Hispanic patients with sarcoidosis experience more depression, chronic pain, sleep problems, and job loss than non-Hispanic patients. The findings suggest that doctors may need to approach treatment differently for Hispanic patients with this condition.

Do patients with central sensitivity syndromes have poor subjective outcomes despite anatomical cure from pelvic organ prolapse surgery?

Vij, Monika, Dua, Anu, Davies, Anthony et al.·International urogynecology journal·2021

This study looked at whether women with ME/CFS, fibromyalgia, or IBS (conditions involving central nervous system sensitivity) had worse outcomes after surgery for pelvic organ prolapse compared to women without these conditions. The researchers found that women with these central sensitivity syndromes reported more persistent symptoms, more pain, and lower satisfaction with surgery even when the surgery was technically successful.

E2 ModerateCohortPEM unclearCross-Sectional

High Prevalence of Perineural Cysts in Patients with Fibromyalgia and Chronic Fatigue Syndrome.

Hulens, Mieke, Bruyninckx, Frans, Dankaerts, Wim et al.·Pain medicine (Malden, Mass.)·2021

Researchers found that small fluid-filled sacs called perineural cysts (Tarlov cysts) near nerve roots in the spine were present in 39% of patients diagnosed with fibromyalgia or ME/CFS—three times more common than in the general population. These cysts may irritate nerves and could potentially explain why some patients with these conditions experience widespread pain and fatigue. This finding suggests that fibromyalgia, ME/CFS, and symptomatic Tarlov cysts might share a similar underlying cause related to spinal fluid pressure.