Proposals for the classification of Chronic pain in ICD-11: Part 1

Post #325 Shortlink:

Part 1

In 2013, the International Association for the Study of Pain (IASP) launched a working group tasked with developing proposals for the classification of chronic pain within ICD-11, for application in primary care, low-resource environments and clinical settings for specialized pain management.

The Classification of Chronic Pain Task Force is working under the auspices of WHO/ICD Revision. The group is co-chaired by IASP President, Prof. Dr. med. Rolf-Detlef Treede, and Winfried Rief PhD, Professor of Clinical Psychology and Psychotherapy, University of Marburg.

The working group held its first meeting in March 2013. At that point, the potential for creating a new Pain chapter  in ICD-11 was reportedly under consideration (Organizing Principles, Classifying pain for healthcare, Carol Cruzan Morton, April 2013).

But the concept of a dedicated pain chapter for ICD-11 appears to have been set aside in preference to expanding the existing Chronic pain classification within the Symptoms, signs, clinical forms, and abnormal clinical and laboratory findings, not elsewhere classified chapter (currently numbered Chapter 21 in the Beta draft).

Under this new Chronic pain disorder section, “…diagnoses in which pain is either the sole or a leading complaint of the patient will be listed.”

Additionally, chronic pain conditions considered neglected in previous ICD versions, for example, chronic cancer pain, chronic neuropathic pain and chronic visceral pain, will be represented under Chronic pain with their own codes.

A simplified version of the proposed framework for use by primary care practitioners was expected to undergo field testing in several countries. A more detailed specialty ICD-11 linearization for use by pain specialists is also envisaged.


What are the most recent proposals from the IASP Chronic Pain Task Force?

In March 2015, the IASP working group published a paper setting out proposals and rationales for the structure of a new Chronic pain section and the disorders classified within it.

Initially, the paper was behind a paywall, but was published under Open Access in June 2015. You can read the paper in html and PDF format here:

A classification of chronic pain for ICD-11. Rolf-Detlef Treede, Winfried Rief et al
Pain. 2015 Jun; 156(6): 1003-7. Published online 2015 Mar 14. PMCID: PMC4450869

Under the proposed framework, chronic pain will be defined as pain that persists or recurs for more than three months.

There are optional specifiers for each diagnosis for recording evidence of psychosocial factors and pain severity. Pain severity can be graded on the basis of pain intensity, pain-related distress, and functional impairment.

“Detailed Explanation of the Proposal” texts for Chronic pain and its 7 child categories have been uploaded to the ICD-11 Beta draft Proposals Mechanism on behalf of the working group.

These are important texts setting out detailed proposals, rationales and criteria and are open for review, comment and suggestions for changes, for which registration with the Beta draft is required. There are links for these texts below but for ease of reference, I am including selected of these texts in .doc format.

Proposed disorder categories

The new ICD section for Chronic pain is proposed to comprise the most common clinically relevant disorders, divided into 7 groups (Fig. 1, Treede et al, 2015).


Chapter 21: Symptoms, signs, clinical forms, and abnormal clinical and laboratory findings, not elsewhere classified 

General symptoms, findings and clinical forms

General symptoms



Chronic pain [Detailed Proposals] [.doc document]

Update: Proposals for Chronic pain replaced with [Detailed Proposals] Antonia Barke 17.09.15

2.1. Chronic primary pain [Detailed Proposals] [.doc document]

Subclass: Mono-site primary chronic pains syndromes [Detailed proposals not available]

Subclass: Multi-site primary chronic pains syndromes [Detailed proposals not available]

  Fibromyalgia [Detailed proposals not available]

2.2. Chronic cancer pain [Detailed Proposals]

2.3. Chronic postsurgical and posttraumatic pain [Detailed Proposals]

2.4. Chronic neuropathic pain [Detailed Proposals]

2.5. Chronic headache and orofacial pain [Detailed Proposals]

2.6. Chronic visceral pain [Detailed Proposals] [.doc document]

2.7. Chronic musculoskeletal pain [Detailed Proposals] [.doc document]


According to its Detailed Proposals text, Chronic primary pain is proposed to be primary parented under Chronic pain and secondary parented to Diseases of the nervous system.

Other chronic pain disorders are proposed to be primary parented under Chronic pain and secondary parented to Neoplasms, Diseases of the nervous system, Diseases of the respiratory system, Diseases of the digestive system, Diseases of the musculoskeletal system and connective tissue or Diseases of the genitourinary system, according to body system.

The “Appendix Structure of the chapter on chronic pain” (page 4 of the Treede et al paper) sets out a complex hierarchy of subclasses.

It’s not evident whether all or selected of these additional subclasses are intended to be added under the disorder categories that are currently displaying in the Beta draft, or whether additional subclasses would be reserved for use in a specialist linearization for chronic pain.

The Treede et al paper describes Chronic primary pain as:

2.1. Chronic primary pain
Chronic primary pain is pain in 1 or more anatomic regions that persists or recurs for longer than 3 months and is associated with significant emotional distress or significant functional disability (interference with activities of daily life and participation in social roles) and that cannot be better explained by another chronic pain condition. This is a new phenomenological definition, created because the etiology is unknown for many forms of chronic pain. Common conditions such as, eg, back pain that is neither identified as musculoskeletal or neuropathic pain, chronic widespread pain, fibromyalgia, and irritable bowel syndrome will be found in this section and biological findings contributing to the pain problem may or may not be present. The term “primary pain” was chosen in close liaison with the ICD-11 revision committee, who felt this was the most widely acceptable term, in particular, from a nonspecialist perspective.

and (under 2.7. Chronic musculoskeletal pain):

…Well-described apparent musculoskeletal conditions for which the causes are incompletely understood, such as nonspecific back pain or chronic widespread pain, will be included in the section on chronic primary pain.


Under two new terms: Mono-site primary chronic pains syndromes and Multi-site primary chronic pains syndromes the IASP working group proposes to locate irritable bowel syndrome; chronic nonspecific back pain; chronic pelvic pain; chronic widespread pain; fibromyalgia, and potentially some other conditions where chronic pain is a feature.

This “new phenomenological definition” appears to be an umbrella diagnosis for a number of the so-called, “functional somatic syndromes.”

There is a considerable amount of psychosomatics in the Detailed Proposals document for Primary chronic pain.

It is unclear whether the intention is to add discrete categories for irritable bowel syndrome; chronic nonspecific back pain; chronic widespread pain, and other diagnoses proposed to be aggregated under the Chronic primary pain term. But at the time of compiling this report, Fibromyalgia is the only term to have been inserted.

In the ICD-11 Beta draft, Irritable bowel syndrome remains at its current location in Diseases of the digestive system chapter, under Irritable bowel syndrome and certain specified functional bowel disorders.

It is therefore unclear whether the ICD-11 Revision Steering Group and the IASP working group have reached consensus over the proposed relocation of Irritable bowel syndrome to the Symptoms, signs chapter, under a new Chronic primary pain parent.

I have requested clarification of current intentions for Irritable bowel syndrome via the Proposal Mechanism comments facility but have received no response.


Proposed new ICD-11 categories

These are the disorder categories as currently entered into the ICD-11 Beta drafting platform under parent class: Pain > Chronic pain for the Foundation Component:

Chapter: Symptoms, signs, clinical forms, and abnormal clinical and laboratory findings, not elsewhere classified

Chronic pain 2 20.08.15

ICD-11 Beta drafting platform, public version: Foundation Component. Accessed August 20, 2015.

A note about discrepancies in terminology between ICD-11 Beta draft and the Treede et al paper: The term, Primary chronic pain, as entered into the Beta draft, is proposed to be amended to Chronic primary pain, in line with the classification structure set out in Table: Appendix Structure of the chapter on chronic pain on page 4 of the Treede et al paper.

The Beta draft’s Mono-site primary chronic pains syndromes and Multi-site primary chronic pains syndromes are termed Localized chronic primary pain (including nonspecific back pain, chronic pelvic pain) and Widespread chronic primary pain (including fibromyalgia syndrome) in the Treede et al paper.

(I have also enquired whether the Mono- and Multi-site primary chronic pains syndromes terms are to be amended to Mono- and Multi-site chronic primary pain syndromes but have received no response.)

If you are a stakeholder in any of the terms proposed to be classified under this new Symptoms, signs chapter section, please scrutinize the IASP Task Force paper and the Detailed Proposals documents and bring these proposals to the attention of your patient organizations.


The G93.3 legacy terms: Postviral fatigue syndrome; Benign myalgic encephalomyelitis; Chronic fatigue syndrome

I have no documentary evidence of intention to locate any of the ICD-10 G93.3 legacy terms under this proposed Symptoms, signs chapter Chronic pain > Chronic primary pain section.

WHO’s, Dr Robert Jakob, told me in June 2015 that he expects TAG Neurology to release proposals and rationales for the classification of the G93.3 legacy terms in September or December, latest. See summary of discussions with WHO personnel, June 19, 2015

Update: Since no proposals and rationales for the ICD-10 G93.3 legacy terms were released in September or December 2015, I contacted ICD’s Dr Robert Jakob. I was told on February 2, 2016 that “[ICD-11 Revsion is] still working on the extensive review and the conclusions.”

Click here for Part 2 Fibromyalgia


Caveats: The ICD-11 Beta drafting platform is not a static document: it is a work in progress, subject to daily edits and revisions, to field test evaluation and to approval by ICD Revision Steering Group and WHO classification experts. Not all new proposals may survive ICD-11 field testing. Chapter numbering, codes and sorting labels currently assigned to ICD categories may change as chapters and parent/child hierarchies continue to be reorganized. The public version of the Beta draft is incomplete: not all Content Model parameters display or have been populated; definitions may be absent, awaiting revision or subject to further revision. The draft may contain errors and category omissions.
For some categories, detailed proposals/rationales/criteria are being posted by Topic Advisory Groups (TAGs) and can be viewed via the Proposals Mechanism, for which registration is required. Additional proposals/suggestions for modifications submitted by work groups or stakeholders which are awaiting review and decisions may also be found via the Proposals Mechanism.

Bloomberg: How Many Billions a Year Will the DSM-5 Cost? Allen Frances, MD

Bloomberg: How Many Billions a Year Will the DSM-5 Cost? Allen Frances, MD

Post #216 Shortlink:

Update: Additional recent articles on DSM-5 development:

Healio Psychiatric Annals > Practice Management > News

DSM-5: a ‘living document’ that may impact practice, patients health

December 21, 2012


How Many Billions a Year Will the DSM-5 Cost?

Illustration by Pete Gamlen

Allen Frances, MD | December 20, 2012

Further responses to the commentary on DSM-5 Somatic Symptom Disorder by Allen Frances and Suzy Chapman published last week on Psychology Today, Huffington Post and Education Update:

IBS Impact blog

Proposed DSM-5 Criteria May Unfairly Label Physical Conditions as Psychological Disorders

“Recently in the IBS and chronic illness community, several professionals and self-advocates have begun expressing concern about proposed changes in the Diagnostic and Statistical Manual for Mental Disorders, commonly known as the DSM…The DSM is revised periodically and the 5th edition is expected to be released in 2013. While there are many controversial proposed changes, one that has received relatively little attention in the mainstream media is particularly alarming in its potential implications for people with chronic illnesses, especially ones that are still scientifically poorly understood, like irritable bowel syndrome or commonly overlapping conditions like fibromyalgia, chronic fatigue syndrome and interstitial cystitis among others…”

Mind Your Body

Moving in the Wrong Direction

Dr Tiffany Taft, Ph.D., Northwestern University | December 13, 2012

“…Rather than repeating what’s in store in DSM 5, this article provides an excellent summary of the proposed changes. It’s really worth taking the time to read, whether you have diabetes, irritable bowel syndrome, lupus, or fibromyalgia. The bottom line is, regardless of the etiology of your chronic illness you are a candidate for the Somatic Symptom Disorder (SDD) diagnosis. If you’re a parent caregiver, your reactions to your child’s illness may be deemed pathological as well…”

The Reporting on Health Member Blog

DSM 5 – Misdiagnosing or Mislabeling of Medical Diseases

Kate Benson | December 19, 2012

Related material

Somatic Symptom Disorder could capture millions more under mental health diagnosis

Submission to Somatic Symptom Disorder Work Group in response to third draft proposals

ICD-11 Beta drafting platform: Update (2)

ICD-11 Beta drafting platform: Update (2): Neurasthenia, Postviral fatigue syndrome (PVFS), Benign myalgic encephalomyelitis (ME), Chronic fatigue syndrome (CFS), Fibromyalgia (FM), Irritable bowel syndrome (IBS)

Post #193 Shortlink:

The information in this report relates to proposals for the World Health Organization’s forthcoming ICD-11, currently scheduled for pilot dissemination in 2015+; it does not apply to the existing ICD-10 or to the forthcoming US specific “clinical modification” of ICD-10, known as ICD-10-CM.

Caveat: The ICD-11 Beta drafting process is a work in progress over the next two to three years. The Beta draft is updated on a daily basis. Parent terms, category terms and sorting codes assigned to categories are subject to change as chapter reorganization progresses. Images and text in this posting may not reflect the most recently assigned categories and codes. This post reflects the Beta draft as it stood at July 25, 2012. Please also read the ICD-11 Beta Draft Caveats.

Post #190 Changes to ICD-11 Beta drafting platform: Bodily Distress Disorders (1) reported on proposals for including three Bodily distress disorder categories in the Somatoform Disorders section of the ICD-11 Beta drafting platform which appear potentially to replace or subsume a number of existing ICD-10 Somatoform Disorder categories.

That post has been revised to reflect clarifications from Professor, Sir David Goldberg, M.D., around the Primary care version of ICD-11 and to include additional material.

The report in this post updates on current proposals for the ICD-11 Beta drafting platform for revision of the following ICD-10 categories: Neurasthenia, Postviral fatigue syndrome (PVFS), Benign myalgic encephalomyelitis (ME), Chronic fatigue syndrome (CFS), Fibromyalgia (FM) and Irritable bowel syndrome (IBS) for the full version of ICD-11.

ICD Revision Steering Group and the various Topic Advisory Groups are developing the ICD-11 Beta draft on a non public access collaborative authoring platform where change histories can be tracked, which looks similar to this:

The publicly viewable version of the Beta drafting platform looks like this:

and displays less information. It can be accessed here:

Beta draft Foundation Component (FC) view:

Beta draft Linearization Morbity (LM) view:

Increased access to content and interaction with the drafting process can be obtained by registering.

Neurasthenia is not classified in DSM-IV and is not proposed to be classified in DSM-5.

In ICD-10, Neurasthenia is classified in Chapter V Mental and behavioural disorders under parents:

F40-F48 Neurotic, stress-related and somatoform disorders

    F48 Other neurotic disorders
        ›  F48.0 Neurasthenia

For ICD-11 Beta, up until July 3, Neurasthenia was also classified under:

Neurotic, stress-related and somatoform disorders

    9S1 Other neurotic disorders
        ›  9S1.1 Neurasthenia

Inclusions: Fatigue syndrome

Exclusions: psychasthenia
postviral fatigue syndrome
malaise and fatigue
asthenia NOS

    9S1.2 Other specified neurotic disorders

Inclusions: Dhat syndrome
Occupational neurosis, including writer’s cramp
Psychasthenic neurosis
Psychogenic syncope

     9S1.3 Neurotic disorder, unspecified

Neurosis NOS


On July 4, all child categories classified under parent class, 9S1 Other neurotic disorders, including Neurasthenia and its Inclusion, Fatigue syndrome, were removed from both the FC and LM view and from the PDF for the Chapter 5 Print version and there is currently no listing for any of these categories and child categories under any parent.

As no “Change history” records display in the public version of the Beta draft, it cannot be determined from what information is available whether these categories are temporarily omitted while this section of Chapter 5 is being reorganized, or whether all or selected of these ICD-10 categories are proposed to be retired for ICD-11 or are destined to be subsumed under the proposed Bodily distress disorders categories that ICD Revision has yet to define.

According to the Goldberg February 2011 report, terms included in the ICD11-PHC version of ICD-11 must have an equivalent disorder in the main classification. In February 2011, it was proposed not to include Neurasthenia in the ICD11-PHC version but to subsume under 13 Distress disorder. (It isn’t clear under which disorder group or subcategory Neurasthenia is proposed to be subsumed for the most recently published iteration for ICD11-PHC.)

Neurasthenia remains listed as an Exclusion to Chapter 5 Generalized anxiety disorder and Chapter 18 Malaise and fatigue but these Exclusions may be awaiting attention, if the intention is to retire a number of ICD-10 terms.

I will update when it becomes apparent what the intention is for these currently missing categories.

ICD-11 Chapter 06: Diseases of the nervous system

Postviral fatigue syndrome, Benign myalgic encephalomyelitis, Chronic fatigue syndrome:

In ICD-10, Postviral fatigue syndrome is classified as a Title term within Volume 1: The Tabular List in Chapter VI: Diseases of the nervous system under G00-G99 Other disorders of the nervous system > G93 Other disorders of brain, and coded at G93.3. See:

Benign myalgic encephalomyelitis is also coded in the Tabular List to G93.3 Postviral fatigue syndrome.

Chronic fatigue syndrome is not classified within the Tabular List but is indexed to G93.3 in Volume 3: The Alphabetical Index.

An unauthorised copy of Volume 3: The Alphabetical Index Version for 2006 can be accessed here: (See Page 528) 

In indexing Chronic fatigue syndrome to G93.3, ICD-10 does not specify whether it views the term as a synonym, subclass or “best coding guess” to Title term, Postviral fatigue syndrome or to Benign myalgic encephalomyelitis.

Nor does ICD-10 specify the relationship between Postviral fatigue syndrome and Benign myalgic encephalomyelitis.

(For ICD-11, a mechanism will be provided to identify whether an inclusion term is a synonym or a subclass.)

In June 2010, I reported that in May 2010, a change of hierarchy had been recorded in the ICD-11 iCAT Alpha drafting platform “Change History” and “Category Discussion Notes” for class: G93.3 Postviral fatigue syndrome.

See these two screenshots from the original iCAT Alpha drafting platform:

Image 1:

Image 2:

From current information in the Beta draft, it would appear that for ICD-11, the proposal is for a change of hierarchy between Postviral fatigue syndrome and Chronic fatigue syndrome with Chronic fatigue syndrome elevated to an ICD-11 Title term, with a Definition (not currently populated) and with potentially up to 12 other descriptive parameters, populated in accordance with the ICD-11 “Content Model.”

There are a number of terms listed under Synonyms to Title term Chronic fatigue syndrome including Benign myalgic encephalomyelitis and Postviral fatigue syndrome.

Mouse hover over the asterisk at the end of Benign myalgic encephalomyelitis and the following hover text displays, “This term is an inclusion term in the linearizations.”

Also listed under “Synonyms” are “chronic fatigue syndrome nos” and “chronic fatigue, unspecified” (both imported from current proposals for locating Chronic fatigue syndrome in Chapter 18: Symptoms and Signs in the forthcoming US specific, ICD-10-CM).

See this Beta drafting platform page:


There is currently no discrete ICD Title term listed for Postviral fatigue syndrome in either the Foundation Component or Linearization Morbidity view and no discrete ICD Title term for Benign myalgic encephalomyelitis.

It remains unconfirmed, but from the Beta draft as it currently stands, it suggests that for ICD-11:

  • Chronic fatigue syndrome is proposed to become the Chapter 06 Title term
  • Benign myalgic encephalomyelitis is specified as an Inclusion term to CFS under “Synonyms”
  • Postviral fatigue syndrome and a number of other terms are listed under “Synonyms” to CFS

ICD-11 terminology:

For definitions of Synonyms, Inclusions, Exclusions and other ICD-11 terminology see the iCAT Glossary:

Fibromyalgia (FM):

In ICD-10, Fibromyalgia is classified under:

Chapter XIII: Diseases of the musculoskeletal system and connective tissue > M79 Other soft tissue disorders > M79 Other soft tissue disorders, not elsewhere classified > M79.7 Fibromyalgia 

ICD-10 Version: 2010:

For ICD-11 Beta draft, Fibromyalgia is currently classified under:

Chapter 13: Diseases of the musculoskeletal system and connective tissue > Soft tissue disorders > Other soft tissue disorders > QG6 Other soft tissue disorders, not elsewhere classified > QG6.7 Fibromyalgia


Irritable bowel syndrome (IBS):

In ICD-10, Irritable bowel syndrome is classified under:

Chapter XI: Diseases of the digestive system > K55-K63 Other diseases of intestines > K58.0 Irritable bowel syndrome with diarrhoea > K58.9 Irritable bowel syndrome without diarrhoea > Irritable bowel syndrome NOS

ICD-10 Version: 2010:

For ICD-11 Beta draft, Irritable bowel syndrome is currently classified under:

Chapter 11: Diseases of the digestive system > Functional gastrointestinal disorders > FS6 Irritable bowel syndrome and other functional bowel disorders > FS6.1 Irritable bowel syndrome 


I shall continue to monitor the Beta drafting process and update on any significant developments for both ICD-11 Chapter 5 and Chapter 6 and for ICD11-PHC for the categories that are the focus of this post and post #190.
References and related material:

1] ICD-10 Version: 2010 Volume 1 Tabular List online:

2] ICD-11 Beta drafting platform:

3] Goldberg, D. Guest editorial. A revised mental health classification for use in general medical settings: the ICD11–PHC 1. International Psychiatry, Page 1, February 2011.

4] 21st Century Global Mental Health by Dr Eliot Sorel, Professor, George Washington University, Washington D.C.
Publication date: August, 2012:
Page 51, Sample Chapter 2:

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