Table of ContentsView AllTable of ContentsFeaturesDifferencesDiagnosisOther SymptomsCan You Have Both?Treatment
Table of ContentsView All
View All
Table of Contents
Features
Differences
Diagnosis
Other Symptoms
Can You Have Both?
Treatment
Fibromyalgia (FMS) and chronic fatigue syndrome (CFS), also called myalgic encephalomyelitis (ME/CFS), are chronic conditions that seem similar but have important differences. Both cause extreme tiredness and body aches, but infibromyalgia, the main symptom is widespread pain and tenderness in the body. InME/CFS, the main problem is severe tiredness that doesn’t go away, even with rest.
Because both conditions include tiredness and other similar symptoms, it’s possible for ME/CFS to be misdiagnosed as fibromyalgia. However, fibromyalgia usually causes more pain, while ME/CFS is more about extreme fatigue. Exercise or physical activity often makes symptoms worse in both conditions, so healthcare providers look carefully at the type and pattern of symptoms to figure out which one a person might have.
What Is Myalgic Encephalomyelitis?Chronic fatigue syndrome is also called myalgic encephalomyelitis, or ME/CFS. The term “CFS” focuses on fatigue as the main symptom but has been criticized for oversimplifying the condition. Adding “ME” highlights possible issues with the brain and immune system, like inflammation and muscle pain. Using both terms together helps show the full picture of the disease.
What Is Myalgic Encephalomyelitis?
Chronic fatigue syndrome is also called myalgic encephalomyelitis, or ME/CFS. The term “CFS” focuses on fatigue as the main symptom but has been criticized for oversimplifying the condition. Adding “ME” highlights possible issues with the brain and immune system, like inflammation and muscle pain. Using both terms together helps show the full picture of the disease.
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Key Differences
Chronic fatigue syndrome and fibromyalgia have many similarities. But each one has distinguishing features that help tell them apart. The key differences can be summarized as follows:
How to Tell Them Apart
While both chronic fatigue syndrome and fibromyalgia involve pain and fatigue, the defining symptom of each condition is different:
Diagnostic Criteria
Once other conditions are excluded, the following criteria specific to each condition can help make a diagnosis.
Chronic Fatigue Syndrome
To be diagnosed with chronic fatigue syndrome, the following four primary symptoms must persist for at least six months:
Plus one of the following:
Fibromyalgia
Fibromyalgia is diagnosed using two questionnaires that assess pain and symptom severity: the Widespread Pain Index (WPI) and the Symptom Severity Scale (SSS).
The WPI evaluates pain across 19 body areas, awarding one point for each painful region. These regions include the:
The SSS assesses the presence and severity of four symptoms, scoring each from 0 (none) to 3 (severe), with a maximum total score of 12. Those symptoms are:
To diagnose fibromyalgia, pain must be present in at least four out of five body regions, with symptoms persisting for at least three months.
Additionally, one of the following score combinations must be met:
This can be a time-consuming process. Not all healthcare providers are comfortablediagnosing fibromyalgia. That means you may need to push for tests or a referral to a specialist.
Additional Symptoms
People with fibromyalgia and ME/CFS often experience additional symptoms beyond their primary diagnostic features, with many of these symptoms overlapping between the two conditions.
In addition to the hallmark feature of ME/CFS—persistent, unrelenting exhaustion—other potential symptoms include:
And, in addition to the hallmark feature of fibromyalgia—widespread, unexplained pain and tenderness—other potential symptoms include:
What Does Fibromyalgia Fatigue Feel Like?Fibromyalgia can feel different to different people. But many people compare the pain to full-body migraines. Your limbs may feel too heavy to lift at times. Your brain may feel slow, cloudy, or hard to focus. The world may be overwhelming to your senses. You may always feel tired, regardless of how much you’ve slept.
What Does Fibromyalgia Fatigue Feel Like?
Fibromyalgia can feel different to different people. But many people compare the pain to full-body migraines. Your limbs may feel too heavy to lift at times. Your brain may feel slow, cloudy, or hard to focus. The world may be overwhelming to your senses. You may always feel tired, regardless of how much you’ve slept.
Can You Have Both CFS and Fibromyalgia?
You can have both chronic fatigue syndrome and fibromyalgia. In fact, many people do.
These conditions are considered “cousins,” of a sort. They belong to the same family of illnesses, which is calledcentral sensitivity syndromes.
The symptoms are extremely similar. So, it can be difficult to tell if you have just one or both of these conditions.
Until there’s better diagnostic testing, it may sometimes be impossible to tell if you have both. It may never even be clear which one you have, either, depending on your specific mix of symptoms.
Fortunately, the treatments are similar. So, you may get the right treatments even if you’re not correctly diagnosed.
How They’re Treated
There’s no standard treatment for ME/CFS or fibromyalgia. Most people end up with multiple types of treatment. It can take a lot of trial and error to come up with a good treatment regimen.
Treating ME/CFS
So far, the Food and Drug Administration (FDA) hasn’t approved any drugs for treating ME/CFS. However, a wide variety of treatment options are available:
Many treatments for ME/CFS, including therapies like CBT and GET, are considered experimental and have limited evidence supporting their effectiveness.
In fact, some studies suggest that only a small percentage of people benefit from them, while others report worsening symptoms.
It is essential to consult a healthcare provider before trying any new treatment to ensure it is safe and appropriate for your specific condition.
Treating Fibromyalgia
The FDA has approved three prescription drugs for fibromyalgia: Cymbalta, Savella, and Lyrica.Many other medications and therapies are used as well, with mixed results in both studies and real-world use:
Before self-treating symptoms with therapies, supplements, or other interventions, consult a healthcare provider to avoid potential medication interactions or unintended effects. Since ME/CFS and fibromyalgia symptoms can mimic other conditions, getting an accurate diagnosis is crucial for safe and effective treatment.
Summary
ME/CFS is known for extreme tiredness that gets worse after doing physical or mental activities, called post-exertional malaise. It also causes poor sleep, trouble focusing, and flu-like symptoms. Unlike FM, ME/CFS often includes dizziness, trouble standing for long periods, and feeling very weak or drained of energy.
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Arthritis and Musculoskeletal and Skin Diseases.What is fibromyalgia?.Johns Hopkins Medicine.Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).Zambolin F, Duro-Ocana P, Faisal A, et al.Fibromyalgia and chronic fatigue syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals.PLoS One. 2022 Oct;17(10):e0276009. doi:10.1371/journal.pone.0276009Pontes-Silva A.Fibromyalgia: A new set of diagnostic criteria based on the biopsychosocial model.Rheumatology. 2024 Feb;63(8):2037–2039. doi:10.1093/rheumatology/keae074Koga M, Shigetoh H, Morioka S.Characteristics of cluters with contrasting relationships between central sensitization-related symptoms and pain.Sci Rep. 2022;12(1):2626. doi:10.1038/s41598-022-06453-8Richman S, Morris M, Broderick G, et al.Pharmaceutical interventions in chronic fatigue syndrome: A literature-based commentary.Clin Ther. 2019 May;41(5):798-805. doi:10.1016/j.clinthera.2019.02.011CDC.Manage myalgic encephalomyelitis/chronic fatigue syndrome.Geraghty K, Jason L, Sunnquist M, Tuller D, Blease C, Adeniji C.The ‘cognitive behavioural model’ of chronic fatigue syndrome: Critique of a flawed model.Health Psychol Open. 2019;6(1):2055102919838907. Published 2019 Apr 23. doi:10.1177/2055102919838907Johns Hopkins Lupus Center.Fibromyalgia medications.Haddad H, Mallepalli N, Scheinuk J, et al.The role of nutrient supplementation in the management of chronic pain in fibromyalgia: A narrative review.Pain Ther. 2021 Apr;10(2):827–848. doi:10.1007/s40122-021-00266-9Additional ReadingAmerican College of Rheumatology.Fibromyalgia.Arthritis Foundation.Treatments worth trying for fibromyalgia.Castro-Marrero J, Sáez-Francàs N, Santillo D, Alegre J.Treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis: all roads lead to Rome.Br J Pharmacol. 2017;174(5):345-369. doi:10.1111/bph.13702Centers for Disease Control and Prevention.Myalgic encephalomyelitis/chronic fatigue syndrome: Evaluation.Wolfe F, Walitt B, Katz R, Häuser W.Symptoms, the nature of fibromyalgia, and Diagnostic and Statistical Manual 5 (DSM-5) defined mental illness in patients with rheumatoid arthritis and fibromyalgia.PLoS ONE. 2014;9(2):e88740. doi:10.1371/journal.pone.0088740
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Arthritis and Musculoskeletal and Skin Diseases.What is fibromyalgia?.Johns Hopkins Medicine.Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).Zambolin F, Duro-Ocana P, Faisal A, et al.Fibromyalgia and chronic fatigue syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals.PLoS One. 2022 Oct;17(10):e0276009. doi:10.1371/journal.pone.0276009Pontes-Silva A.Fibromyalgia: A new set of diagnostic criteria based on the biopsychosocial model.Rheumatology. 2024 Feb;63(8):2037–2039. doi:10.1093/rheumatology/keae074Koga M, Shigetoh H, Morioka S.Characteristics of cluters with contrasting relationships between central sensitization-related symptoms and pain.Sci Rep. 2022;12(1):2626. doi:10.1038/s41598-022-06453-8Richman S, Morris M, Broderick G, et al.Pharmaceutical interventions in chronic fatigue syndrome: A literature-based commentary.Clin Ther. 2019 May;41(5):798-805. doi:10.1016/j.clinthera.2019.02.011CDC.Manage myalgic encephalomyelitis/chronic fatigue syndrome.Geraghty K, Jason L, Sunnquist M, Tuller D, Blease C, Adeniji C.The ‘cognitive behavioural model’ of chronic fatigue syndrome: Critique of a flawed model.Health Psychol Open. 2019;6(1):2055102919838907. Published 2019 Apr 23. doi:10.1177/2055102919838907Johns Hopkins Lupus Center.Fibromyalgia medications.Haddad H, Mallepalli N, Scheinuk J, et al.The role of nutrient supplementation in the management of chronic pain in fibromyalgia: A narrative review.Pain Ther. 2021 Apr;10(2):827–848. doi:10.1007/s40122-021-00266-9Additional ReadingAmerican College of Rheumatology.Fibromyalgia.Arthritis Foundation.Treatments worth trying for fibromyalgia.Castro-Marrero J, Sáez-Francàs N, Santillo D, Alegre J.Treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis: all roads lead to Rome.Br J Pharmacol. 2017;174(5):345-369. doi:10.1111/bph.13702Centers for Disease Control and Prevention.Myalgic encephalomyelitis/chronic fatigue syndrome: Evaluation.Wolfe F, Walitt B, Katz R, Häuser W.Symptoms, the nature of fibromyalgia, and Diagnostic and Statistical Manual 5 (DSM-5) defined mental illness in patients with rheumatoid arthritis and fibromyalgia.PLoS ONE. 2014;9(2):e88740. doi:10.1371/journal.pone.0088740
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institute of Arthritis and Musculoskeletal and Skin Diseases.What is fibromyalgia?.Johns Hopkins Medicine.Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).Zambolin F, Duro-Ocana P, Faisal A, et al.Fibromyalgia and chronic fatigue syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals.PLoS One. 2022 Oct;17(10):e0276009. doi:10.1371/journal.pone.0276009Pontes-Silva A.Fibromyalgia: A new set of diagnostic criteria based on the biopsychosocial model.Rheumatology. 2024 Feb;63(8):2037–2039. doi:10.1093/rheumatology/keae074Koga M, Shigetoh H, Morioka S.Characteristics of cluters with contrasting relationships between central sensitization-related symptoms and pain.Sci Rep. 2022;12(1):2626. doi:10.1038/s41598-022-06453-8Richman S, Morris M, Broderick G, et al.Pharmaceutical interventions in chronic fatigue syndrome: A literature-based commentary.Clin Ther. 2019 May;41(5):798-805. doi:10.1016/j.clinthera.2019.02.011CDC.Manage myalgic encephalomyelitis/chronic fatigue syndrome.Geraghty K, Jason L, Sunnquist M, Tuller D, Blease C, Adeniji C.The ‘cognitive behavioural model’ of chronic fatigue syndrome: Critique of a flawed model.Health Psychol Open. 2019;6(1):2055102919838907. Published 2019 Apr 23. doi:10.1177/2055102919838907Johns Hopkins Lupus Center.Fibromyalgia medications.Haddad H, Mallepalli N, Scheinuk J, et al.The role of nutrient supplementation in the management of chronic pain in fibromyalgia: A narrative review.Pain Ther. 2021 Apr;10(2):827–848. doi:10.1007/s40122-021-00266-9
National Institute of Arthritis and Musculoskeletal and Skin Diseases.What is fibromyalgia?.
Johns Hopkins Medicine.Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
Zambolin F, Duro-Ocana P, Faisal A, et al.Fibromyalgia and chronic fatigue syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals.PLoS One. 2022 Oct;17(10):e0276009. doi:10.1371/journal.pone.0276009
Pontes-Silva A.Fibromyalgia: A new set of diagnostic criteria based on the biopsychosocial model.Rheumatology. 2024 Feb;63(8):2037–2039. doi:10.1093/rheumatology/keae074
Koga M, Shigetoh H, Morioka S.Characteristics of cluters with contrasting relationships between central sensitization-related symptoms and pain.Sci Rep. 2022;12(1):2626. doi:10.1038/s41598-022-06453-8
Richman S, Morris M, Broderick G, et al.Pharmaceutical interventions in chronic fatigue syndrome: A literature-based commentary.Clin Ther. 2019 May;41(5):798-805. doi:10.1016/j.clinthera.2019.02.011
CDC.Manage myalgic encephalomyelitis/chronic fatigue syndrome.
Geraghty K, Jason L, Sunnquist M, Tuller D, Blease C, Adeniji C.The ‘cognitive behavioural model’ of chronic fatigue syndrome: Critique of a flawed model.Health Psychol Open. 2019;6(1):2055102919838907. Published 2019 Apr 23. doi:10.1177/2055102919838907
Johns Hopkins Lupus Center.Fibromyalgia medications.
Haddad H, Mallepalli N, Scheinuk J, et al.The role of nutrient supplementation in the management of chronic pain in fibromyalgia: A narrative review.Pain Ther. 2021 Apr;10(2):827–848. doi:10.1007/s40122-021-00266-9
American College of Rheumatology.Fibromyalgia.Arthritis Foundation.Treatments worth trying for fibromyalgia.Castro-Marrero J, Sáez-Francàs N, Santillo D, Alegre J.Treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis: all roads lead to Rome.Br J Pharmacol. 2017;174(5):345-369. doi:10.1111/bph.13702Centers for Disease Control and Prevention.Myalgic encephalomyelitis/chronic fatigue syndrome: Evaluation.Wolfe F, Walitt B, Katz R, Häuser W.Symptoms, the nature of fibromyalgia, and Diagnostic and Statistical Manual 5 (DSM-5) defined mental illness in patients with rheumatoid arthritis and fibromyalgia.PLoS ONE. 2014;9(2):e88740. doi:10.1371/journal.pone.0088740
American College of Rheumatology.Fibromyalgia.
Arthritis Foundation.Treatments worth trying for fibromyalgia.
Castro-Marrero J, Sáez-Francàs N, Santillo D, Alegre J.Treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis: all roads lead to Rome.Br J Pharmacol. 2017;174(5):345-369. doi:10.1111/bph.13702
Centers for Disease Control and Prevention.Myalgic encephalomyelitis/chronic fatigue syndrome: Evaluation.
Wolfe F, Walitt B, Katz R, Häuser W.Symptoms, the nature of fibromyalgia, and Diagnostic and Statistical Manual 5 (DSM-5) defined mental illness in patients with rheumatoid arthritis and fibromyalgia.PLoS ONE. 2014;9(2):e88740. doi:10.1371/journal.pone.0088740
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