Chronic fatigue

From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history
Source: Chronic fatigue syndrome: A review (Balachander et al.) 2014.[1]

Chronic fatigue (CF) is a symptom that can be caused many diseases, illnesses and medications. Chronic fatigue is common in a large number of illnesses including multiple sclerosis, fibromyalgia, rheumatoid arthritis, diabetes, depression, and chronic fatigue syndrome.

Chronic fatigue means the patient experiences significant and long-term fatigue, which may or may not have a known medical explanation. It should be distinguished from the disease called chronic fatigue syndrome (CFS), of which chronic fatigue is only one of many symptoms.[2] The two terms are not interchangeable. Wikipedia contains separate pages for each.

What is a syndrome?[edit | edit source]

A syndrome is a number of symptoms that commonly occur together, and may or may not be caused by the same underlying disease process.

If there is only one symptom, then the word syndrome cannot be used. For example, Chronic regional pain syndrome involves multiple symptoms including pain (e.g., skin and muscle symptoms) so should not be referred to as chronic pain, which is just one of many symptoms.

Chronic fatigue vs. Chronic fatigue syndrome and Idiopathic Chronic Fatigue[edit | edit source]

Chronic Fatigue Syndrome (CFS) is a distinct neurological disease, and is not the same as chronic fatigue, or long-term fatigue with no known cause (ICF).
Source: Son, C-G (2019). Differential diagnosis between “chronic fatigue” and “chronic fatigue syndrome”. Integrative Medicine Research, 8(2), 89-91. Suggested algorithm for chronic fatigue, ICF and CFS. License: CC-BY-ND-NC.

Dr. Jarred Younger explains chronic fatigue and begins by stating "Fatigue is not a disease and it is not even a symptom. So fatigue is a alarm system and the most general alarm system the body has."[3] Webinar with Jarred Younger, Ph.D. (Video starts with quote @6:04 and Younger discusses fatigue until @7:54)

Idiopathic chronic fatigue (ICF) refers to medically unexplained chronic fatigue lasting at least 6 months that does not meet the criteria for chronic fatigue syndrome, for example post-exertional malaise (PEM) may be mild or non-existent, and orthostatic intolerance or cognitive impairment may not be present.[2]

Post-Viral Fatigue vs Post-Viral Fatigue Syndrome[edit | edit source]

Post-viral Fatigue refers to any Fatigue that started immediately after a virus, whether it is short-term or long-lasting.

Post-Viral Fatigue Syndrome or PVFS is an alternative name for the neurological disease myalgic encephalomyelitis or chronic fatigue syndrome. Post-Viral Fatigue Syndrome is a the main index term used in the World Health Organization's diagnostic manual. Any of the different diagnostic criteria for ME or CFS can be used, provided all the symptoms started together after a viral infection which is now gone.[4]

Terms[edit | edit source]

Cause of symptoms Duration and type of symptoms Illness name
Unknown - not investigated yet Tiredness for weeks or a few months. Tired all the time, Exhaustion, or Fatigue
Lifestyle issues or burnout Tiredness or other types of fatigue, for a few months Fatigue
Virus Fatigue, for weeks or a few months Post-Viral Fatigue
Another illness e.g. MS, depression, heart failure, fibromyalgia, etc Fatigue, usually disabling. Long term. Chronic fatigue
Unknown - tests did not find a cause Fatigue, any severity. Long term, usually over 6 months. Idiopathic chronic fatigue, unexplained chronic fatigue, or Chronic fatigue (symptom)
Virus Fatigue, worsens with activity, disabling. Long term, over 6 months Post-Viral Fatigue Syndrome or ME/CFS if diagnostic criteria are fully met, otherwise idiopathic chronic fatigue
Chronic fatigue syndrome or ME, whether caused by a virus or not Fatigue, worsens with activity, disabling. Long term, over 6 months Chronic fatigue syndrome or ME/CFS if diagnostic criteria are fully met, otherwise idiopathic chronic fatigue

Examples of incorrect usage[edit | edit source]

In these examples the neurological disease chronic fatigue syndrome is erroneously referred to using the name of only one of the many symptoms involved, chronic fatigue. Chronic fatigue is a symptom, not a disease. Idiopathic chronic fatigue is the term that should be used to refer to unexplained chronic fatigue. Chronic fatigue is the term to use to refer to long term fatigue which is not necessarily caused by ME/CFS.

Notable studies[edit | edit source]

  • 2002, A factor analysis of chronic fatigue symptoms in a community-based sample (Full text)
  • 2014, Chronic fatigue syndrome: A review[1] (Full Text)
  • 2019, Differential diagnosis between “chronic fatigue” and “chronic fatigue syndrome”[2] (Full source)

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 Singh, Shubh Mohan; Sarkar, Siddharth; Rao, Pradyumna; Balachander, Srinivas (July 1, 2014). "Chronic fatigue syndrome: A review". Medical Journal of Dr.D.Y. Patil University. 7 (4): 415. doi:10.4103/0975-2870.135252. ISSN 0975-2870.
  2. 2.0 2.1 2.2 Son, Chang-Gue (June 2019). "Differential diagnosis between "chronic fatigue" and "chronic fatigue syndrome"". Integrative medicine research. 8 (2): 89–91. doi:10.1016/j.imr.2019.04.005. ISSN 2213-4220. PMID 31193269.
  3. Younger, Jarred (May 20, 2016). "Webinar with Jarred Younger, Ph.D." YouTube. SolveCFS.
  4. World Health Organization. "Postviral fatigue syndrome | ICD-11 - Mortality and Morbidity Statistics". icd.who.int. WHO. Retrieved October 14, 2018.
  5. Hodgekiss, Anna (February 11, 2015). "Chronic fatigue IS 'a real and serious disease', say doctors". Mail Online. Retrieved September 10, 2018.
  6. Spencer, Ben (February 9, 2016). "People with chronic fatigue are 6 times more likely to commit suicide". Mail Online. Retrieved September 10, 2018.
  7. Yang, Xiu Hong; Zhang, Bao Long; Gu, Yan Hong; Zhan, Xiao Li; Guo, Li Li; Jin, Hui Min (2018). "Association of sleep disorders, chronic pain, and fatigue with survival in patients with chronic kidney disease: a meta-analysis of clinical trials". Sleep Medicine. 51: 59–65. doi:10.1016/j.sleep.2018.06.020. ISSN 1389-9457.
  8. Sigurdsson MD, Alex F. (November 8, 2017). "19 Important Causes of Fatigue - Tiredness and Chronic Fatigue Explained". docsopinion.com. Retrieved January 30, 2019.
  9. Klimas, Nancy (June 21, 2014). "ME/CFS Diagnosis and Name with Dr. Nancy Klimas". YouTube. ME/CFS Community.