ICD-10 Chapter V: Mental and Behavioural Disorders

(In ICD-11, this chapter is known as “Chapter 06”.)

ICD-10 Chapter V is also published as a separate publication known as the “Blue Book” and available as a PDF. This expands on the descriptions and includes diagnostic guidelines.

ICD-10 Classification of Mental and Behavioural Disorders Clinical descriptions and diagnostic guidelines: http://www.who.int/classifications/icd/en/bluebook.pdf

This is how “Fatigue syndrome” and “Neurasthenia” are classified in ICD-10 Chapter V:

Tabular List ICD-10 Version:2010

Note exclusion of Malaise and fatigueR53 ) and Postviral fatigue syndrome ( G93.3 ).

(Please refer to the “Blue Book” and to ICD-10 Online Version: 2010 for full categories, category descriptions, inclusions and exclusions.)


Chapter V

Mental and behavioural disorders


Neurotic, stress-related and somatoform disorders



F45  Somatoform disorders

F45.0  Somatization disorder

F45.1  Undifferentiated somatoform disorder

F45.8  Other somatoform disorders

F45.9  Somatoform disorder, unspecified

Psychosomatic disorder NOS

F48  Other neurotic disorders

F48.0  Neurasthenia  [Ed: Lengthy textual description of symptoms for neurasthenia omitted]

Fatigue syndrome  [Ed: Note: not “postviral”; not “chronic”]

Use additional code, if desired, to identify previous physical illness. 

Excludes:  asthenia NOS ( R53 )

burn-out ( Z73.0 )

malaise and fatigue ( R53 )

postviral fatigue syndrome ( G93.3 )

psychasthenia ( F48.8 )

Correspondence between DSM-IV and ICD-10

There is a degree of correspondence between the current DSM-IV Somatoform Disorders categories and the equivalent section in ICD-10: Chapter V. This table sets out how the two classification systems currently correspond for Somatoform Disorders [1].

Current DSM-IV Codes and Categories for Somatoform Disorders and ICD-10 Equivalents

[1] Source: Mayou R, Kirmayer LJ, Simon G, Kroenke K, Sharpe M: Somatoform disorders: time for a new approach in DSM-V. Am J Psychiat. 2005;162:847–855. [Neurasthenia (classified in ICD-10: Chapter V at F48.0) is not categorized in DSM-IV.] 

ICD-10 Chapter XVIII

(In ICD-11, this chapter will be known as “Chapter 21”.)

Note the following classifications under R53 Malaise and fatigue. See “Notes” regarding R53.82 and US ICD-10-CM.

Note exclusion of Fatigue syndrome ( F48.0 ) and Postviral fatigue syndromeG93.3 ).


Chapter XVIII

Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified


General symptoms and signs



R53 Malaise and fatigue

Asthenia NOS



· chronic

· nervous

General physical deterioration



Excludes:  debility:

· congenital ( P96.9 )

· senile ( R54 )

exhaustion and fatigue (due to)(in):

· combat ( F43.0 )

· excessive exertion ( T73.3 )

· exposure ( T73.2 )

· heat ( T67.- )

· neurasthenia ( F48.0 )

· pregnancy ( O26.8 )

· senile asthenia ( R54 )

fatigue syndrome ( F48.0 )

· postviral ( G93.3 )

What are the issues?

For ICD-11, all three Volumes of ICD will be electronically published and integrable.

For most recent udpate on proposals for ICD-11 see: Post #96: July 3, 2011: http://wp.me/pKrrB-1eb

This site will monitor the progress of the revision of ICD-10 Chapter VI: Diseases of the nervous system (the Neurological chapter) with specific reference to the three classifications coded to G93.3 in Volume 1: The Tabular List: Postviral fatigue syndrome; Benign myalgic encephalomyelitis; and indexed to code G93.3 in Volume 3: The Alphabetical Index: Chronic fatigue syndrome.

Content in ICD-11 will be populated for parameters, in accordance with the ICD-11 Content Model Style Guide. There is the potential for considerably more content to be included for diseases, disorders and syndromes in ICD-11 than appears in ICD-10, including Definition, Inclusions and Causal Mechanisms.

It is not known how much additional information might be included in ICD-11 for the three terms currently classified at, or indexed to, G93.3. Content will need to be monitored as it is generated, as will any changes to the hierarchy between these three terms, as will specification of the relationships between the three terms.

This site will monitor the population of content proposed for inclusion in ICD-11 for these three entities.

This site makes no assumptions about what proposals might be made by the Topic Advisory Group for Mental and Behavioural Disorders (TAG MH) for the revision of the Somatoform Disorders section in ICD-10 Chapter V; or whether, and to what extent, the Topic Advisory Group for Mental and Behavioural Disorders might seek to achieve congruency between category names, glossary descriptions and criteria in Chapter V with those within a restructured DSM Somatoform Disorders section (proposed to be renamed “Somatic Symptom Disorders”) or whatever name might eventually be adopted for this section in DSM-5.

This site will monitor the progress of the revision of the Somatoform Disorders section in ICD-10 Chapter V with specific reference to those categories currently classified between F45 – F48.0 and also monitor the revision of the corresponding DSM-IV Somatoform Disorders section which the DSM-5 Somatic Symptom Disorders Work Group is proposing to rename and potentially restructure.


Part Two

Forthcoming US “Clinical Modification” ICD-10-CM

ICD-10-CM, a “Clinical Modification” of ICD-10, is scheduled for implementation on October 1, 2013 and has been subject to partial code freeze since October 1, 2011. It will replace the US specific ICD-9-CM.

Current and long-standing proposals for ICD-10-CM propose classifying Chronic fatigue syndrome under Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99) at R53.82

For a history of the coding of PVFS, ME and CFS in ICD to March 2001, see the CDC document:

A Summary of Chronic Fatigue Syndrome and Its Classification in the International Classification of Diseases
Prepared by the Centers for Disease Control and Prevention, National Center for Health Statistics, Office of the Center Director, Data Policy and Standards, CDC archive document, March 2001.

NCHS proposals, as they stood at March 2001, as set out in this document, were later superseded.

For the most recent ICD-10-CM proposals see:

CDC site: International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM)

The 2012 update of ICD-10-CM is now available and replaces the December 2011 release. [2]

[2] Although this release of ICD-10-CM is now available for public viewing, the codes in ICD-10-CM are not currently valid for any purpose or use. The effective implementation date for ICD-10-CM (and ICD-10-PCS) is October 1, 2013. Updates to this version are anticipated prior to implementation of ICD-10-CM.

Partial Code Freeze

A Partial Code Freeze for ICD-10-CM was implemented on October 1, 2011. For information on the implications for Partial Code Freeze please refer to this CDC website page:


and here: http://www.cms.gov/ICD9ProviderDiagnosticCodes/03_meetings.asp

and see this PDF document Partial Code Freeze

Discussion of whether and when to implement a Partial Code Freeze for ICD-10-CM was tabled for discussion at the March 9, 2010 public meeting of the ICD-9-CM Coordination and Maintenance Committee. Transcript here from Page 10 onwards; includes contributions from Darrel Regier, MD, Vice-chair, DSM-5 Task Force, American Psychiatric Association.


Proposed classifications and codings for ICD-10-CM (2012 update, replaces December 2011 version)



Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)

This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.

[…]  See document for full text

Note: This is not the ICD-10-CM Mental and Behavioural chapter which is:


Mental and behavioral disorders (F01-F99)

Includes: disorders of psychological development

Excludes2: symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)


Tabular List of Diseases and Injuries   Page 954   2012 Release

R53 Malaise and fatigue


R53.8 Other malaise and fatigue

Excludes1: combat exhaustion and fatigue (F43.0)

                    congenital debility (P96.9)

exhaustion and fatigue due to:

depressive episode (F32.-)

excessive exertion (T73.3)

exposure (T73.2)

heat (T67.-)

pregnancy (O26.8-)

recurrent depressive episode (F33)

senile debility (R54)

R53.81 Other malaise

            Chronic debility

                    Debility NOS

General physical deterioration

Malaise NOS

Nervous debility

                    Excludes1: age-related physical debility (R54)

R53.82 Chronic fatigue, unspecified

     Chronic fatigue syndrome NOS

                    Excludes1: postviral fatigue syndrome (G93.3)

R53.83 Other fatigue

     Fatigue NOS

                    Lack of energy



ICD-10-CM CHAPTER 6 Page 271   2012 release

Diseases of the nervous system (G00-G99)



symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

G93 Other disorders of brain


G93.3 Postviral fatigue syndrome

   Benign myalgic encephalomyelitis

          Excludes1: chronic fatigue syndrome NOS (R53.82)

Continued on Page 3

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