FIELD E ; Pathology Code 



Columns 18, 19, 20, 21, 



22, 23, 24, and 25 



classification in the Field E symbols for non-infectious pathologies. Therefore, the coding of the 

 primary anatomical classification of non-infectious diseases has been shifted to Field E, using, how- 

 ever, the classification and symbols established in Field H. 



This primary anatomical designation is the second part of the total Field E non-infectious 

 pathology symbol, represented by the 2nd, 3rd, and 4th units (Columns 19, 20, and 21). 



Coding of pathology in Field E has as its primary objective the identification of the specific 

 condition treated, basing identity on anatomical and etiological relationships. Field H is used as a 

 supplement to Field E in the case of pathology Identification, in addition to being used to code the 

 anatomical part specifically responding to the test compound. 



4. Relation between the anatomical part of the non-infectious pathology symbol and Field H 



In coding the identity of a pathology, coding in Field H indicates the location of the pathology, 

 whether infectious or a tumor or even in the case of non-infectious pathologies whose primary or typical 

 anatomical association is indicated in Field E. Field H-l is coded with the organ responding to, or 

 candidate for responding to, the chemical treatment and this is assumed to be the organ site of the 

 pathology; however, if an organ responds which happens to be an organ other than the site of the 

 treated pathology, the organ coded in Field H-l will not represent the site of the pathology, the coding 

 of which must be shifted to Field H-2. 



Thus, two areas are available for coding non-infectious pathology sites, (1) Columns 19, 20, 

 and 21 of Field E and (2) Field H, a feature lending versatility to code identification of infectious 

 pathologies, as the following explains. 



Many general non-infectious pathological conditions affect either the entire body or are non- 

 specific and can affect any of a large number of sites; these particular conditions are assigned symbols 

 with no specific site other than "body as a whole" (Symbol BOO), indicated in Columns 19, 20, and 21 

 of Field E. When such a general pathology is restricted, in the case treated, to only a given anatomical 

 part, the specific location can be coded in Field H. Certain pathologies may be primarily disorders of 

 specific anatomical parts, coded in Columns 19, 20, and 21 of Field E, rather than of the entire body 

 generally, yet, in the case treated, an organ which is secondarily affected by the disease (and which 

 responds to chemical treatment) may be an organ of another type; the second organ can only be coded 

 in Field H (see the third, fifth, and sixth of the following examples). The outline on the following page 

 demonstrates these relations of Fields E and H in coding the anatomical aspects of pathologies, using 

 liver disorders as an example. In these examples of identifying pathologies by code, attention is 

 called to the anatomy entry in Field E (the part of the pathology symbol underlined) and the anatomy 

 entry in Field H-l and to the way these various combinations represent different statements of test 

 conditions or results. 



5. Part HI of the Pathology Code symbol (5th and 6th units, Columns 22 and 23); etiology 



Providing code symbols for specific pathological conditions is beset with problems arising 

 from the nature of pathology and its resistance to classification. The organism is a physiological unit 

 whose normal well being is dependent on the balanced and coordinated functioning of all its parts. 

 When an initial disorder occurs, or when the organism is attacked by infection, the coordinate 

 physiology is disrupted and a chain of subsidiary disorders may occur, contemporary with or subsequent 

 to the initial disorder. The secondary disorders, while definable as entities, all too frequently bear 

 characteristics peculiar to their origins in the primary disorder and, as a consequence, pathology 

 nomenclature has evolved to embrace these origins in definitions. 



In the case of both infectious and non-infectious diseases, each definition of a pathology in 

 the Code list is made in terms of the origin of the disease, in addition to the anatomical site. For 

 infectious diseases, the origin is defined by the symbol identifying the infecting organism, taken from 

 Taxonomy Code. 



When an item, included in the list of non- infectious pathologies, defines a pathological state 

 that may have any of two or more known origins, it is assigned a symbol which Identifies the disease 



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