Editing Nosology

{{Short description|Branch of medicine that deals with classification of diseases}}
{{For|the study of the nose|Rhinology}}
{{For|the parody of nose classification|Nasology}}

{{Use dmy dates|date=January 2020}}
'''Nosology''' ({{etymology|grc|''νόσος'' (nosos)|disease||-''λογία'' (-logia)|study of}}) is the branch of [[medical science]] that deals with the [[Medical classification|classification of diseases]].  Fully classifying a medical condition requires knowing its cause (and that there is only one cause), the effects it has on the body, the symptoms that are produced, and other factors.  For example, [[influenza]] is classified as an infectious disease because it is caused by a virus, and it is classified as a respiratory infection because the virus infects and damages certain tissues in the respiratory tract.  The more that is known about the disease, the more ways the disease can be classified nosologically.

'''Nosography''' is a description whose primary purpose is enabling a diagnostic label to be put on the situation.<ref>{{Cite book|last1=Stanghellini|first1=Giovanni|url=https://books.google.com/books?id=_TpLAAAAQBAJ&dq=nosography&pg=PT25|title=One Century of Karl Jaspers' General Psychopathology|last2=Fuchs|first2=Thomas|date=2013-07-04|publisher=OUP Oxford|isbn=978-0-19-150647-5|language=en|quote=The aim of nosography is the description of single illnesses to allow their diagnosis.  Nosography outlines provisional and conventional characteristics of a syndrome and thereby serves the goal of an empirical diagnosis.}}</ref><ref>{{Cite book|last1=Schramme|first1=Thomas|url=https://books.google.com/books?id=zeYfAAAAQBAJ|title=Philosophy and Psychiatry|last2=Thome|first2=Johannes|date=2012-08-09|publisher=[[Walter de Gruyter]]|isbn=978-3-11-090576-2|pages=1|language=en}}</ref>  As such, a nosographical entity need not have a single cause.  For example, inability to speak due to advanced dementia and an inability to speak due to a stroke could be nosologically different but nosographically the same.

==Types of classification==

Diseases may be classified by cause, [[pathogenesis]] ([[mechanism (biology)|mechanism]] by which the disease progresses), or by [[symptom]](s).{{citation needed|date=June 2022}}

Alternatively, diseases may be classified according to the [[organ system]] involved, though this is often complicated since many diseases affect more than one organ.

Traditionally diseases were defined as [[syndrome]]s by their symptoms. When more information is available, they are also defined by the damage they produce. When cause is known, they are better defined by their cause, though still important are their characteristics. This leads to a branching differentiation in which a clinical syndrome (pattern of signs and symptoms) can come to be understood as a nonspecific finding shared by a group of [[disease entity|disease entities]] or [[endotype]]s. For example, concepts such as [[murrain]] and [[the grippe]] that were formerly undifferentiable to humans and thus understood as a single disease later can be logically unraveled as separate diseases with similar [[clinical presentation]]s. Thus, nosology is dynamic, reclassifying as science advances.{{citation needed|date=June 2022}}

The advent of [[molecular biology]] brought a further reclassification potential with the concept of molecularly defined diseases, defined by their molecular characteristics. This concept was introduced in 1949, with the seminal paper, "[[Sickle Cell Anemia, a Molecular Disease]]",<ref>L Pauling, H Itano, SJ Singer, I Wells. [http://osulibrary.oregonstate.edu/specialcollections/coll/pauling/blood/papers/1949p.15.html "Sickle Cell Anemia, a Molecular Disease"]. ''Science'', 25 November 1949, vol. 110, no. 2865, pp. 543–548.</ref> in ''Science'' magazine, [[Linus Pauling]], [[Harvey Itano]] and their collaborators laid the groundwork for establishing the field of molecular medicine. Molecular medicine, in concert with genetics and genomics as aspects of molecular biology, provided new instances of the theme that clinical presentations that humans formerly interpreted as a single disease can be subclassified into a group of disease entities or endotypes. For example, many [[Online Mendelian Inheritance in Man|OMIM]] database entries show the pattern of disease name XYZ with types identified as XYZ1 (involving sequence variants in gene A), XYZ2 (involving sequence variants in gene B), XYZ3 (involving sequence variants in gene C), XYZ4 (involving sequence variants in both genes B and C), and so on.{{citation needed|date=June 2022}}

==Coding systems==

Several classifications of diseases have been historically proposed, and normally all of them assign a code to every supported disease. Some of them codify diseases following the path of the classification tree, and others like SNOMED use a multifactor classification system.{{citation needed|date=June 2022}}

The most known coding system is the [[World Health Organization]] [[ICD-10|ICD-Series]], but there are other accepted classifications like [[DOCLE]], [[NANDA]] or [[SNOMED]].<ref>{{cite web|url=https://www.mayo.edu/research/documents/biostat-83pdf/doc-10026715 |title=Comparison of Mayo Clinic Coding Systems |date=14 December 2010 |website=www.mayo.edu|access-date=11 June 2019}}</ref> Historically there were others like the [[Berkson Coding System]] that are not maintained anymore.{{citation needed|date=June 2022}}

There are also coding systems for symptoms present in the diseases and biological findings. They are normally included in medical dictionaries, also with a codification system. Some of them are [[Medical Subject Headings|MeSH]] (Medical Subject Headings), [[COSTART]] (Coding Symbols for Thesaurus of Adverse Reaction Terms) or MedDRA (Medical Dictionary for Regulatory Activities)<ref>{{cite journal|pmc=3149405|title=Medical Coding in Clinical Trials|first=Deven|last=Babre|date=1 January 2010|journal=Perspect Clin Res|volume=1|issue=1|pages=29–32|pmid=21829779}}</ref> Other systems like [[Current Procedural Terminology]] do not deal directly with diseases but with the related procedures.{{citation needed|date=June 2022}}

==Extended nosology and general medical conditions==

In a wide sense, nosology deals not only with diseases, but with any kind of [[medical condition]], like [[injury|injuries]], [[lesions]] or [[disorder (medicine)|disorders]].<ref>{{cite journal | author = Starkstein S E, Leentjens A F G | year = 2008 | title = The nosological position of apathy in clinical practice | journal = J Neurol Neurosurg Psychiatry | volume = 79 | issue = 10| pages = 1088–1092 | doi = 10.1136/jnnp.2007.136895 | pmid = 18187477 | doi-access = free }}</ref><ref>Abenhaim, Lucien et al. The Prognostic Consequences in the Making of the Initial Medical Diagnosis of Work-Related Back Injuries. Spine Journal, 1995</ref>

Medical conditions, like diseases, can be defined by cause, [[pathogenesis]] ([[mechanism (biology)|mechanism]] by which the disease is caused), or by a collection of [[symptom]]s, [[medical sign]]s and [[biomarker]]s, particularly when the other two definitions are not available ([[idiopathic]] diseases).

{{Anchor|Condition}}
{{Anchor|Disorder}}
{{Anchor|Disease}}
{{Anchor|Illness}}
{{Anchor|Sickness}}
{{Anchor|Syndrome}}
{{Anchor|Injury}}
{{Anchor|Lesion}}

From a nosological point of view, medical conditions can be divided in disorders, diseases, syndromes, lesions and injuries, each one with some specific meaning, as listed at ''[[Disease#Terminology|Disease § Terminology]]''.<!--Cross-reference. The list that was formerly here was a [[Wikipedia:Content forking|fork]] attempting to cover the same info separately. The anchors have been retained to ensure that all links thereto remain working and useful.-->

==History==

Ancient medical treatises had a variety of different ways of classifying and grouping illnesses. Chinese texts like the ''[[Huangdi Neijing]]'' categorized diseases by which of the [[Wuxing (Chinese philosophy)|atmospheric influences]] was believed to be responsible for them.<ref>{{cite book|title=Leprosy in China: A History|last1=Leung|first1=Angela Ki Che|last2=Liang|first2=Qizi|pages=17–22|publisher=Columbia University Press|year=2009|isbn=9780231123006}}</ref> Many ancient Greek, Mesopotamian, Roman, and Egyptian authors categorized diseases by the body parts they affected, while others divided diseases into [[Acute (medicine)|acute]] or chronic illnesses.<ref name="Cambridge">{{cite book|chapter=Nosology|author=Amneris Roselli|editor=Peter E. Pormann|title=The Cambridge Companion to Hippocrates|publisher=Cambridge University Press|year=2018|isbn=9781107068209}}</ref> Mental disorders were classified into categories like [[mania]] and [[paranoia]] by [[Hippocrates]],<ref>{{cite journal|journal=Journal of Medical Ethics and History of Medicine |title=Health care practices in ancient Greece: The Hippocratic ideal|year=2014|volume=7|page=6|first1=Christos F.|last1=Kleisiaris|first2=Chrisanthos|last2=Sfakianakis|first3=Ioanna V. |last3=Papathanasiou|pmc=4263393|pmid=25512827}}</ref> and this system was utilized by later authors like [[Najib ad-Din Samarqandi]].<ref>{{cite book|title=Psychiatric Diagnosis and Classification|publisher=Wiley|isbn=978-0471496816|editor=Mario Maj|chapter=Psychiatric Diagnosis and Classification in Developing Countries|last1=Murthy|first1=R. Srinivasa|last2=Wig|first2=Narendra N.|date=22 April 2002}}</ref>

Many popular ancient disease classification systems largely relied upon [[Four humours|humorism]],<ref name="Cambridge" /> which carried over into medieval times. Early attempts to develop more comprehensive approaches to the classification of diseases were made by [[Jean Fernel]] in the 16th century.<ref>{{cite book|title=History of the Statistical Classification of Diseases and Causes of Death|publisher=CDC|year=2011|first1=Iwao M.|last1=Moriyama|first2=Ruth M. |last2=Loy|first3=Alastair H.T.|last3=Robb-Smith|chapter-url=https://www.cdc.gov/nchs/data/misc/classification_diseases2011.pdf|chapter=Development of the Classification of Diseases}}</ref> Early modern nosological efforts grouped [[disease]]s by their [[symptom]]s, whereas modern systems focus on grouping diseases by the [[anatomy]] and cause involved.

In the 17th century, the English physician [[Thomas Sydenham]] was the first to propose a syndrome-based classification of diseases. For Sydenham a disease and a syndrome were equivalent concepts.<ref>{{Cite journal|last=Smith|first=R.|date=13 April 2002|title=In search of "non-disease"|journal=BMJ|volume=324|issue=7342|pages=883–885|doi=10.1136/bmj.324.7342.883|pmid=11950739|pmc=1122831}}</ref>

In the 18th century, the [[taxonomist]] [[Carl Linnaeus]], [[François Boissier de Sauvages de Lacroix|Francois Boissier de Sauvages]], and psychiatrist [[Philippe Pinel]] developed an early classification of physical illnesses. In the late 19th century, [[Emil Kraepelin]] and then [[Jacques Bertillon]] developed their own nosologies. Bertillon's work, classifying causes of [[death]], was a precursor of the modern code system, the [[ICD|International Classification of Diseases]].

==Applications==
*  Nosology is used extensively in [[public health]], to allow [[Epidemiology|epidemiological]] studies of public health issues.  Analysis of [[death certificate]]s requires nosological coding of causes of death.
*  Nosological classifications are used in medical administration, such as filing of health insurance claims, and patient records.

==See also==
* [[Clinical coder]]
* [[Diagnosis code]]
* [[Differential diagnosis]]
* [[ICD|International Statistical Classification of Diseases and Related Health Problems]] (ICD)
** [[ICD-10]] (ICD 10th Revision)
* [[Medical classification]]
* [[Pathology]] (study of disease)
* [[:Category:Diseases and disorders]] (Wikipedia's categorization of diseases)
* [[Symptomatology]] – study of individual symptoms

==References==
{{Reflist}}

==Further reading==
* {{Cite journal
| doi = 10.1164/rccm.200203-204PP
| pmid = 12598211
| title = Nosology for Our Day
| journal = American Journal of Respiratory and Critical Care Medicine
| volume = 167
| issue = 5
| pages = 678–683
| year = 2003
| last1 = Snider | first1 = G. L.
}}
* [http://www.ssrn.com/author=510356 C. S. Herrman], [https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1652925 "The Bipolar Spectrum"], SSRN (Social Science Research Network, 5 August 2010)

== External links ==
{{Commons category}}
* [https://web.archive.org/web/20000817130958/http://www.who.int/whosis/icd10/ International Classification of Diseases (ICD-10)] by the [[World Health Organization]]

{{Authority control}}

[[Category:Nosology| ]]
[[Category:Medical terminology]]