Primary symptom (compulsory for diagnosis):

  • Overwhelming post-exertional malaise as a result of minimal cognitive, emotional or physical effort. This exhaustion may occur immediately after activity or be delayed by hours or days.

A range of simultaneous symptoms (several of the following):

  • Sleep problems/disturbances;
  • Widespread pain and headaches;
  • Neurocognitive dysfunction:  short term memory loss, concentration impaired, confusion, disorientation, hypersensitivity to light and sound, emotional overload;
  • Problems with dizziness and balance;
  • Problems with body temperature (including intolerance of extremes of temperature) and weight;
  • Recurrent flu-like symptoms (e.g. sore throat);
  • Gastrointestinal Problems (e.g. nausea, abdominal pain, bloating, irritable bowel syndrome (IBS))
  • Sensitivities to food, medications, odours or certain chemicals.

The manifestation of symptoms is highly individualised. There may be marked fluctuation of symptom severity from mild, moderate to severe (vide infra) and this hierarchy changes from day to day and hour to hour. A relatively small (25%)(ME Alliance report) proportion of ME/CFS patients suffer in the severe end of the ME/CFS spectrum. For them the range and severity of symptoms are quite marked and they may be house or bed-bound and require a wheelchair to be mobile.

The International Consensus Primer for Medical Practitioners (2012) is the standard recommended for diagnosis and management of ME/CFS in Australia and globally. It includes diagnostic criteria, laboratory tests and management principles. It also contains a fully expanded list of symptoms.


What is ME/CFS?


What causes ME/CFS?

Who gets ME/CFS?

Further reading

Further Reading and References

ME Alliance, ME/CFS Diagnosis: “Delay Harms Health Early diagnosis: why is it so important? A report from the M.E. Alliance“, Dr Charles Shepherd.

Johnston, S. C., et al. “Epidemiological characteristics of chronic fatigue syndrome/myalgic encephalomyelitis in Australian patients.Clin Epidemiol, 2016, 8: 97-107.

Gotts, Z. M., et al. “The experience of sleep in chronic fatigue syndrome: A qualitative interview study with patients.Br J Health Psychol, 2016, 21(1): 71-92.

Cvejic, E., et al. “Cognitive Dysfunction in Chronic Fatigue Syndrome: a Review of Recent Evidence.Curr Rheumatol Rep, 2016, 18(5): 24.

Giloteaux, L., et al. “Reduced diversity and altered composition of the gut microbiome in individuals with myalgic encephalomyelitis/chronic fatigue syndrome.Microbiome, 2016, 4(1): 30.

Jason, L. A., et al. “Problems in defining post-exertional malaise.J Prev Interv Community, 2015, 43(1): 20-31.

Bested, A. C. and L. M. Marshall. “Review of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: an evidence-based approach to diagnosis and management by clinicians.Rev Environ Health, 2015, 30(4): 223-249.

Snodgrass, K., et al. “Sleep Disturbances in Pediatric Chronic Fatigue Syndrome: A Review of Current Research.J Clin Sleep Med, 2015, 11(7): 757-764.

Maes, M. “A new case definition of Neuro-Inflammatory and Oxidative Fatigue (NIOF), a neuroprogressive disorder, formerly known as chronic fatigue syndrome or Myalgic Encephalomyelitis: results of multivariate pattern recognition methods and external validation by neuro-immune biomarkers.Neuro Endocrinol Lett, 2015, 36(4): 320-329.

Sulheim, D., et al. “Cognitive dysfunction in adolescents with chronic fatigue: a cross-sectional study.Arch Dis Child, 2015, 100: 838–844.

Jason, L. A., et al. “Chronic fatigue syndrome versus sudden onset myalgic encephalomyelitis.J Prev Interv Community, 2015, 43(1): 62-77.

Jackson, M. L., et al. “Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study.Sleep Sci, 2015, 8(3): 124-133.

Gotts, Z. M., et al. “The Association between Daytime Napping and Cognitive Functioning in Chronic Fatigue Syndrome.PLoS One, 2015, 10(1): e0117136.

Twisk Frank, N. M. “Underperformance of myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) patients at neurocognitive tests should be assessed objectively without an a priori judgment about the etiology.J Psychosom Res, 2014, 76(4): 339.

Santamarina-Perez, P., et al. “Neuropsychological impairment in female patients with chronic fatigue syndrome: a preliminary study.Appl Neuropsychol Adult, 2014, 21(2): 120-127.

Mariman, A. N., et al.  “Sleep in the chronic fatigue syndrome.Sleep Medicine Reviews, 2013, 17(3), 193-199.

Lavigne, G. J. “Thread emerges from three papers on pain, chronic fatigue, and sleep: Avenues for deeper understanding.Sleep Medicine Reviews, 2013, 17(3), 169-171.

Baraniuk, J. N., et al. “A Chronic Fatigue Syndrome (CFS) severity score based on case designation criteria.Am J Transl Res, 2013, 5(1): 53-68.

Jackson, M. L. and D. Bruck. “Sleep abnormalities in chronic fatigue syndrome/myalgic encephalomyelitis: a review.J Clin Sleep Med, 2012, 8(6): 719-728.

Stewart, J. M., et al. “Postural neurocognitive and neuronal activated cerebral blood flow deficits in young chronic fatigue syndrome patients with postural tachycardia syndrome.Am. J. Physiol., 2012, 302(3, Pt. 2): H1185-H1194.

Rahman, K., et al. “Sleep-wake behavior in chronic fatigue syndrome.Sleep, 2011, 34(5): 671-678.

Kishi, A., et al. “Sleep-stage dynamics in patients with chronic fatigue syndrome with or without fibromyalgia.Sleep, 2011, 34(11): 1551-1560.

Kawatani, J., et al. “Cognitive dysfunction and mental fatigue in childhood chronic fatigue syndrome–a 6-month follow-up study.Brain Dev, 2011, 33(10): 832-841.

Constant, E. L., et al. “Cognitive deficits in patients with chronic fatigue syndrome compared to those with major depressive disorder and healthy controls.Clin Neurol Neurosurg, 2011, 113(4): 295-302.

Ravindran, M. K., et al. “Migraine headaches in chronic fatigue syndrome (CFS): comparison of two prospective cross-sectional studies.BMC Neurol, 2011, 11: 30.

Togo, F., et al. “Sleep is not disrupted by exercise in patients with chronic fatigue syndromes.Med Sci Sports Exerc, 2010, 42(1): 16-22.

VanNess, J. M., et al. “Postexertional malaise in women with chronic fatigue syndrome.J Womens Health (Larchmt), 2010, 19(2): 239-244.

Libman, E., et al. “Sleep apnea and psychological functioning in chronic fatigue syndrome.J Health Psychol, 2009, 14(8): 1251-1267.

Togo, F., et al. “Sleep structure and sleepiness in chronic fatigue syndrome with or without coexisting fibromyalgia.Arthritis Res Ther, 2008, 10(3): R56.

Kishi, A., et al. “Dynamics of sleep stage transitions in healthy humans and patients with chronic fatigue syndrome.Am. J. Physiol., 2008, 294(6, Pt. 2): R1980-R1987.

Reeves, W. C., et al. “Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study.BMC Neurol, 2006, 6: 41.

Guilleminault, C., et al. “Chronic fatigue, unrefreshing sleep and nocturnal polysomnography.Sleep Medicine, 2006, 7(6): 513-520.

Capuron, L., et al. “Cognitive dysfunction relates to subjective report of mental fatigue in patients with chronic fatigue syndrome.Neuropsychopharmacology, 2006, 31(8): 1777-1784.

Unger, E. R., et al. “Sleep assessment in a population-based study of chronic fatigue syndrome.BMC Neurol, 2004, 4: 6.

Fischler, B. “Review of clinical and psychobiological dimensions of the chronic fatigue syndrome: differentiation from depression and contribution of sleep dysfunctions.Sleep Medicine Reviews, 1999, 3(2), 131-146.