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Fibromyalgia

Fibromyalgia as a perioperative risk modifier (corpus-synthesised).

39 citationsUpdated Sep 2026
Illustration: Fibromyalgia

For patients: a plain-language version of this topic is available. See the patient guide.

Overview

Fibromyalgia is a syndrome characterized by chronic widespread pain, hyperalgesia, and allodynia [13]. It is associated with symptoms such as fatigue, sleep disturbance, and impaired cognition [13]. The majority of individuals with fibromyalgia experience fatigue and describe it as more severe than normal tiredness [20]. Daytime napping is commonly used by people with fibromyalgia [6]. Current evidence supports the view that at least some fibromyalgia symptoms are associated with brain dysfunctions or alterations [5]. Findings are consistent with the hypothesis that fibromyalgia is related to a general dysregulation of the central nervous system [1]. Fibromyalgia patients have norepinephrine-evoked pain [3]. In a specific ethnic group, a disabling form of fibromyalgia is associated with a particular SCN9A sodium channel gene variant [12]. The apparent paradox of fewer myoelectrical manifestations of fatigue in fibromyalgia is the electrophysiological expression of muscle remodelling in terms of the prevalence of slow conducting fatigue-resistant type I fibres [15]. Indications suggest that the gut microbiota may play a role in fibromyalgia within the emerging field of the gut-musculoskeletal axis [7], although there is a paucity of quality research regarding the association between fibromyalgia and the gut microbiome [7].

The prevalence of fibromyalgia in the French population is 1.6% [4]. In a low socioeconomic status population assisted by the public primary health care system, the prevalence is 4.4% [9]. Persons identified with criteria-based fibromyalgia have severe symptoms [2]. Most persons identified with criteria-based fibromyalgia (73%) have not received a clinical diagnosis of fibromyalgia [2]. Men with fibromyalgia syndrome reported more severe symptoms compared to women [14]. Men with fibromyalgia syndrome reported decreased physical function compared to women [14]. Men with fibromyalgia syndrome reported lower quality of life compared to women [14]. The prevalence of post-COVID-19 in fibromyalgia patients is similar to that in patients with other rheumatic diseases [10].

Fibromyalgia poses a substantial economic and human burden on patients and society [29].

Background & Causes

Clinical Presentation and Epidemiology

Fibromyalgia is a syndrome characterized by chronic widespread pain, hyperalgesia, and allodynia, accompanied by fatigue, sleep disturbance, and impaired cognition [13]. Despite the severity of symptoms in persons identified with criteria-based fibromyalgia, 73% have not received a clinical diagnosis of fibromyalgia [2]. Clinical outcomes vary by sex; men with fibromyalgia syndrome report more severe symptoms, decreased physical function, and lower quality of life compared to women [14].

Pathophysiology and Neurobiology

The condition is related to a general dysregulation of the central nervous system [1], with at least some symptoms associated with brain dysfunctions or alterations [5]. Specific genetic factors contribute to severity, as a disabling form of fibromyalgia is associated with a particular SCN9A sodium channel gene variant in a specific ethnic group [12]. The pathophysiology involves neurochemical, immunological, and nutritional factors [36], although the specific role of cytokines in fibromyalgia syndrome remains unclear [40]. Emerging research suggests the gut microbiota may play a role within the gut-musculoskeletal axis [7]. Additionally, both cardiac output and arteriovenous oxygen difference contribute to lower peak oxygen uptake in fibromyalgia patients [22].

Psychological and Environmental Factors

Psychological stressors significantly impact symptom severity. Repeated cognitive stress increases pain intensity in fibromyalgia patients [19]. In situations involving imposed stress, including sympathetic activation and putative anticipatory stress, patients exhibit elevated muscle activity, particularly in the trapezius [27]. Negative affectivity independently predicts both central sensitization symptoms and disease severity, as reflected by Fibromyalgia Impact Questionnaire scores [30]. Furthermore, the stage of chronicity serves as an important moderator of psychological vulnerability for fibromyalgia impact [31].

Symptoms & Presentation

Fibromyalgia is associated with a general dysregulation of the central nervous system [1]. The clinical presentation includes fatigue, sleep disturbance, and impaired cognition [13]. Patients also experience norepinephrine-evoked pain [3]. Sleep difficulty symptoms are independently associated with clinically-meaningful decrements in both mental and physical health-related quality of life [23]. Negative affectivity independently predicts central sensitization symptoms and disease severity [30].

Epidemiological data indicate a prevalence of 1.6% in the French population [4]. In low socioeconomic status populations assisted by the public primary health care system, the prevalence is 4.4% [9].

Sex-based differences: Men with fibromyalgia syndrome report more severe symptoms, decreased physical function, and lower quality of life compared to women [14].

Management

Pharmacological Interventions

Trazodone significantly improves fibromyalgia severity and associated symptomatology when used in combination with pregabalin [16]. In doses higher than those usually prescribed as hypnotic, the utility of trazodone in fibromyalgia management surpasses its hypnotic activity [32].

Exercise and Physical Therapy

Higher physical fitness is consistently associated with lower fibromyalgia severity in women with fibromyalgia [25]. Patients with fibromyalgia are able to activate skeletal muscle metabolism during a short, moderate bout of exercise and are not resistant to training effects [28]. For the prescription of exercises in the threshold intensity, 52% to 60% HRR or 75% to 80% HRMax must be used in sedentary women with fibromyalgia syndrome [34]. Traditional Chinese Exercise exhibits significant efficacy in ameliorating pain, enhancing sleep quality, and alleviating symptoms of anxiety and depression in fibromyalgia patients [35]. An intervention based on pain neuroscience education and exercise is feasible and seems effective in primary care [37]. High-quality scientific works are required to highlight physiotherapy as one of the most recommended treatment options for fibromyalgia syndrome [38].

Self-Management and Behavioral Interventions

It is feasible to recruit people with fibromyalgia from Primary Care to participate in a randomised controlled trial testing a Fibromyalgia Self-management Programme in a community setting [8]. In patients with fibromyalgia, a multidisciplinary inpatient self-management programme had no effect on psychological distress, functional and symptomatic consequences and self-efficacy, except for a small short-term effect on skills and behaviour that are important for managing and participating in health care [24]. Improvements from health and wellness coaching do not typically occur spontaneously in fibromyalgia patients, suggesting that health and wellness coaching deserves further consideration as an intervention for fibromyalgia [21]. Further studies with better treatment quality and adequate methodological quality assessing all key domains of fibromyalgia syndrome are necessary to clarify the efficacy of hypnosis/guided imagery in fibromyalgia syndrome [39].

Assessment and Monitoring

A multidimensional assessment for patients with fibromyalgia demonstrates comprehensiveness and validity, showing significant correlations between various assessment tools and the Fibromyalgia Impact Questionnaire [17]. The MDF-Fibro-17 reliably measures 5 domains of fibromyalgia-related fatigue and meets or exceeds predefined acceptable thresholds for evidence of reliability, validity, and responsiveness to changes in clinical status [18]. Sleep difficulty symptoms were independently associated with clinically-meaningful decrements in mental and physical health-related quality of life among the fibromyalgia population [23]. Daytime napping is commonly used by people with fibromyalgia, and evidence-based guidelines on the use of daytime napping in people with chronic pain are urgently needed [6].

Pathophysiology and Comorbidities

Fibromyalgia patients show elevated muscle activity, in particular trapezius activity, in situations with imposed stress, including sympathetic activation, and putative anticipatory stress [27].

Key Considerations

Epidemiology and Prevalence

Fibromyalgia is a common condition with a prevalence of 1.6% in the French population [4]. Prevalence is higher in low socioeconomic status populations assisted by the public primary health care system, where it reaches 4.4% [9]. Despite the severity of symptoms in persons identified with criteria-based fibromyalgia, most (73%) have not received a clinical diagnosis of fibromyalgia [2].

Pathophysiology and Neurobiology

Research indicating that the gut microbiota may play a role in fibromyalgia within the emerging field of the gut-musculoskeletal axis is currently of poor quality [7].

Assessment and Measurement

Psychological constructs related to pain in fibromyalgia have been evaluated for correlations and predictive validity regarding function and pain over a one-year follow-up [11].

Management and Interventions

Pharmacological and non-pharmacological interventions show variable efficacy. Trazodone significantly improved fibromyalgia severity and associated symptomatology in a two-phase, 24-week, open-label uncontrolled study [16]. A one-week multidisciplinary inpatient self-management programme had no effect on psychological distress, functional and symptomatic consequences, and self-efficacy, except for a small short-term effect on skills and behaviour important for managing and participating in health care [24]. Improvements from health and wellness coaching do not typically occur spontaneously in fibromyalgia patients, suggesting the intervention deserves further consideration [21]. Evidence-based guidelines on the use of daytime napping in people with chronic pain are urgently needed given the common use of daytime napping in people with fibromyalgia [6].

Patient Experience

Fibromyalgia syndrome is a condition that intrudes upon many aspects of patients' lives and is little understood, evoking uneasiness in health care staff and placing great demands on resources [33].

Key Evidence

  • [L3] Our findings are consistent with the hypothesis that fibromyalgia is related to a general dysregulation of the central nervous system. [1] (10.1186/s12891-016-1331-1)
  • [L3] Persons identified with criteria-based fibromyalgia have severe symptoms, but most (73%) have not received a clinical diagnosis of fibromyalgia. [2] (10.1371/journal.pone.0138024)
  • [L2] Fibromyalgia patients have norepinephrine-evoked pain. [3] (10.1186/1471-2474-3-2)
  • [L4] Fibromyalgia is a common condition with a prevalence of 1.6% in the French population, corroborating figures published in the European literature. [4] (10.1186/1471-2474-12-224)
  • [L5] Current evidence supports the view that at least some fibromyalgia symptoms are associated with brain dysfunctions or alterations, giving the long-held 'it is all in your head' view of the disorder a new meaning. [5] (10.1155/2012/585419)
  • [L4] Given the common use of daytime napping in people with fibromyalgia evidence based guidelines on the use of daytime napping in people with chronic pain are urgently needed. [6] (10.1186/s12891-015-0464-y)
  • [L1] The results suggest there is a paucity of quality research in this area, with indications that the gut microbiota may play a role in fibromyalgia within the emerging field of the gut-musculoskeletal axis. [7] (10.1186/s12891-020-03201-9)
  • [L2] It is feasible to recruit people with fibromyalgia from Primary Care to participate in a randomised controlled trial testing the FSMP in a community setting. [8] (10.1186/s12891-022-05529-w)
  • [L4] Fibromyalgia is prevalent in the low socioeconomic status population assisted by the public primary health care system with a prevalence of 4.4%. [9] (10.1186/1471-2474-10-64)
  • [L3] The prevalence of post-COVID-19 in fibromyalgia patients is similar to that in patients with other rheumatic diseases. [10] (10.1186/s12891-022-05436-0)
  • [L3] The study aims to assess the importance of pain-related psychological constructs on function and pain in patients with fibromyalgia, specifically evaluating correlations and predictive validity over a one-year follow-up. [11] (10.1186/1471-2474-12-4)
  • [L3] In this ethnic group, a disabling form of fibromyalgia is associated with a particular SCN9A sodium channel gene variant. [12] (10.1186/1471-2474-13-23)
  • [L5] Fibromyalgia is a syndrome characterized by chronic widespread pain, hyperalgesia, and allodynia, along with symptoms such as fatigue, sleep disturbance, and impaired cognition. [13] (10.1016/b978-0-7020-4086-3.00033-3)
  • [L3] Men with FMS reported more severe symptoms, decreased physical function, and lower quality of life compared to women. [14] (10.1053/sarh.2000.8363)
  • [L3] The apparent paradox of fewer myoelectrical manifestations of fatigue in fibromyalgia is the electrophysiological expression of muscle remodelling in terms of the prevalence of slow conducting fatigue-resistant type I fibres. [15] (10.1186/1471-2474-10-78)
  • [L4] Trazodone significantly improved fibromyalgia severity and associated symptomatology. [16] (10.1186/1471-2474-12-95)
  • [L3] The study demonstrates the comprehensiveness and validity of a multidimensional assessment for patients with fibromyalgia, showing significant correlations between various assessment tools and the Fibromyalgia Impact Questionnaire. [17] (10.1186/s12891-025-09270-y)
  • [L4] The MDF-Fibro-17 reliably measures 5 domains of FM-related fatigue and psychometric evaluation confirms that this measure meets or exceeds each of the predefined acceptable thresholds for evidence of reliability, validity, and responsiveness to changes in clinical status. [18] (10.1186/s12891-017-1545-x)
  • [L3] Repeated cognitive stress increases pain intensity in fibromyalgia patients. [19] (10.1186/s12891-021-04013-1)
  • [L4] The majority of individuals with FM who participated in this study experience fatigue and describe it as more severe than normal tiredness. [20] (10.1186/1471-2474-11-216)
  • [L4] Such improvements do not typically occur spontaneously in FM patients, suggesting that HWC deserves further consideration as an intervention for FM. [21] (10.1186/s12891-016-1316-0)
  • [L3] Both cardiac output and arteriovenous oxygen difference contribute to lower peak oxygen uptake in fibromyalgia patients. [22] (10.1186/s12891-023-06589-2)
  • [L3] Among the FM population, sleep difficulty symptoms were independently associated with clinically-meaningful decrements in mental and physical HRQoL. [23] (10.1186/1471-2474-13-199)
  • [L1] The study shows that in patients with fibromyalgia the self-management programme had no effect on psychological distress, functional and symptomatic consequences and self-efficacy, except for a small short-term effect on skills and behaviour that are important for managing and participating in health care. [24] (10.1186/1471-2474-13-189)
  • [L4] Our results suggest that higher physical fitness is consistently associated with lower FM severity in women with FM. [25] (10.1016/j.apmr.2015.03.015)
  • [L3] FM patients show elevated muscle activity (in particular trapezius activity) in situations with imposed stress, including sympathetic activation, and putative anticipatory stress. [27] (10.1186/1471-2474-14-97)
  • [L2] Hence, patients with FM were able to activate their skeletal muscle metabolism during a short, moderate bout of exercise and were not resistant to training effects. [28] (10.1186/s12891-017-1402-y)
  • [L4] In a sample of 88 patients with FM from France, we found that FM poses a substantial economic and human burden on patients and society. [29] (10.1186/1471-2474-13-22)
  • [L4] Multivariate regression analyses revealed that negative affectivity—one of the core subcomponents of TDP—independently predicted both central sensitization symptoms and disease severity, as reflected by Fibromyalgia Impact Questionnaire (FIQ) scores. [30] (10.1186/s12891-026-09687-z)
  • [L4] These findings provide preliminary evidence that stage of chronicity is an important moderator of psychological vulnerability for FM impact and should be taken into account by tailoring psychological interventions. [31] (10.1186/1471-2474-11-251)
  • [L4] In doses higher than those usually prescribed as hypnotic, the utility of trazodone in fibromyalgia management surpasses its hypnotic activity. [32] (10.1186/1471-2474-11-204)
  • [L4] FMS is a condition that intrudes upon many aspects of patients' lives and is little understood, evoking uneasiness in health care staff and placing great demands on resources. [33] (10.1186/1471-2474-10-124)
  • [L2] For the prescription of exercises in the threshold intensity, 52% to 60% HRR or 75% to 80% HRMax must be used in sedentary women with fibromyalgia syndrome. [34] (10.1186/1471-2474-11-54)
  • [L1] Traditional Chinese Exercise (TCE) exhibits significant efficacy in ameliorating pain, enhancing sleep quality, and alleviating symptoms of anxiety and depression in fibromyalgia patients. [35] (10.1186/s12891-024-07194-7)
  • [L3] This research highlights FMS's complex nature, involving neurochemical, immunological, and nutritional factors. [36] (10.1186/s12891-025-08337-0)
  • [L3] An intervention based on PNE and exercise in patients with FM is feasible and seems effective in PC. [37] (10.1186/s12891-022-05284-y)
  • [L2] High-quality scientific works are required to highlight physiotherapy as one of the most recommended treatment options for this syndrome. [38] (10.1186/s12891-016-1364-5)
  • [L1] Further studies with better treatment quality and adequate methodological quality assessing all key domains of FMS are necessary to clarify the efficacy of H/GI in FMS. [39] (10.1186/1471-2474-12-133)
  • [L1] The pathophysiological role of cytokines in FMS is still unclear. [40] (10.1186/1471-2474-12-245)

References

[1] Are persons with fibromyalgia or other musculoskeletal pain more likely to report hearing loss? A HUNT study. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1331-1

[2] The Prevalence and Characteristics of Fibromyalgia in the 2012 National Health Interview Survey. PLOS ONE. 2015. DOI: 10.1371/journal.pone.0138024

[3] Norepinephrine-evoked pain in fibromyalgia. A randomized pilot study ISCRTN70707830. BMC Musculoskeletal Disorders. 2002. DOI: 10.1186/1471-2474-3-2

[4] Prevalence of fibromyalgia in France: a multi-step study research combining national screening and clinical confirmation: The DEFI study (Determination of Epidemiology of FIbromyalgia). BMC Musculoskeletal Disorders. 2011. DOI: 10.1186/1471-2474-12-224

[5] Neurobiology Underlying Fibromyalgia Symptoms. Pain Research and Treatment. 2012. DOI: 10.1155/2012/585419

[6] Daytime napping associated with increased symptom severity in fibromyalgia syndrome. BMC Musculoskeletal Disorders. 2015. DOI: 10.1186/s12891-015-0464-y

[7] Determining the association between fibromyalgia, the gut microbiome and its biomarkers: A systematic review. BMC Musculoskeletal Disorders. 2020. DOI: 10.1186/s12891-020-03201-9

[8] A feasibility randomised controlled trial of a Fibromyalgia Self-management Programme for adults in a community setting with a nested qualitative study (FALCON). BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05529-w

[9] Prevalence of fibromyalgia in a low socioeconomic status population. BMC Musculoskeletal Disorders. 2009. DOI: 10.1186/1471-2474-10-64

[10] Prevalence of post-COVID-19 in patients with fibromyalgia: a comparative study with other inflammatory and autoimmune rheumatic diseases. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05436-0

[11] Correlational analysis and predictive validity of psychological constructs related with pain in fibromyalgia. BMC Musculoskeletal Disorders. 2011. DOI: 10.1186/1471-2474-12-4

[12] A SCN9A gene-encoded dorsal root ganglia sodium channel polymorphism associated with severe fibromyalgia. BMC Musculoskeletal Disorders. 2012. DOI: 10.1186/1471-2474-13-23

[13] Fibromyalgia. Handbook of Clinical Neurology. 2014. DOI: 10.1016/b978-0-7020-4086-3.00033-3

[14] Fibromyalgia syndrome in men. Seminars in Arthritis and Rheumatism. 2000. DOI: 10.1053/sarh.2000.8363

[15] Central motor control failure in fibromyalgia: a surface electromyography study. BMC Musculoskeletal Disorders. 2009. DOI: 10.1186/1471-2474-10-78

[16] Trazodone plus pregabalin combination in the treatment of fibromyalgia: a two-phase, 24-week, open-label uncontrolled study. BMC Musculoskeletal Disorders. 2011. DOI: 10.1186/1471-2474-12-95

[17] Comprehensiveness and validity of a multidimensional assessment of patients with fibromyalgia: a prospective cohort study. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-09270-y

[18] Multidimensional daily diary of fatigue-fibromyalgia-17 items (MDF-fibro-17): part 2 psychometric evaluation in fibromyalgia patients. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1545-x

[19] Muscle activity and acute stress in fibromyalgia. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04013-1

[20] Fatigue in fibromyalgia: a conceptual model informed by patient interviews. BMC Musculoskeletal Disorders. 2010. DOI: 10.1186/1471-2474-11-216

[21] A pilot study of health and wellness coaching for fibromyalgia. BMC Musculoskeletal Disorders. 2016. DOI: 10.1186/s12891-016-1316-0

[22] Cardiac output and arteriovenous oxygen difference contribute to lower peak oxygen uptake in patients with fibromyalgia. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-023-06589-2

[23] The association of sleep difficulties with health-related quality of life among patients with fibromyalgia. BMC Musculoskeletal Disorders. 2012. DOI: 10.1186/1471-2474-13-199

[24] Effects of a one week multidisciplinary inpatient self-management programme for patients with fibromyalgia: a randomised controlled trial. BMC Musculoskeletal Disorders. 2012. DOI: 10.1186/1471-2474-13-189

[25] Association of Physical Fitness With Fibromyalgia Severity in Women: The al-Ándalus Project. Archives of Physical Medicine and Rehabilitation. 2015. DOI: 10.1016/j.apmr.2015.03.015

[27] Trapezius activity of fibromyalgia patients is enhanced in stressful situations, but is similar to healthy controls in a quiet naturalistic setting: a case-control study. BMC Musculoskeletal Disorders. 2013. DOI: 10.1186/1471-2474-14-97

[28] Acute effects of physical exercise on the serum insulin-like growth factor system in women with fibromyalgia. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1402-y

[29] Societal and individual burden of illness among fibromyalgia patients in France: Association between disease severity and OMERACT core domains. BMC Musculoskeletal Disorders. 2012. DOI: 10.1186/1471-2474-13-22

[30] Psychosocial correlates of central sensitization and kinesiophobia: the role of Type D personality in fibromyalgia — a cross-sectional study. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09687-z

[31] Stages of chronicity in fibromyalgia and pain catastrophising: a cross-sectional study. BMC Musculoskeletal Disorders. 2010. DOI: 10.1186/1471-2474-11-251

[32] Trazodone for the treatment of fibromyalgia: an open-label, 12-week study. BMC Musculoskeletal Disorders. 2010. DOI: 10.1186/1471-2474-11-204

[33] Patients' experiences of living with and receiving treatment for fibromyalgia syndrome: a qualitative study. BMC Musculoskeletal Disorders. 2009. DOI: 10.1186/1471-2474-10-124

[34] Intensity level for exercise training in fibromyalgia by using mathematical models. BMC Musculoskeletal Disorders. 2010. DOI: 10.1186/1471-2474-11-54

[35] Effects of traditional Chinese exercise therapy on pain scores, sleep quality, and anxiety-depression symptoms in fibromyalgia patients: a systematic review and meta-analysis. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07194-7

[36] Serum choline, leptin and interleukin-6 levels in fibromyalgia syndrome-induced pain: a case–control study. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-08337-0

[37] Effectiveness of a group intervention using pain neuroscience education and exercise in women with fibromyalgia: a pragmatic controlled study in primary care. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05284-y

[38] Effectiveness of Aquatic Therapy vs Land-based Therapy for Balance and Pain in Women with Fibromyalgia: a study protocol for a randomised controlled trial. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-016-1364-5

[39] Efficacy of hypnosis/guided imagery in fibromyalgia syndrome - a systematic review and meta-analysis of controlled trials. BMC Musculoskeletal Disorders. 2011. DOI: 10.1186/1471-2474-12-133

[40] Systematic review with meta-analysis: cytokines in fibromyalgia syndrome. BMC Musculoskeletal Disorders. 2011. DOI: 10.1186/1471-2474-12-245

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1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.