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A place to decipher acronyms and complex words that you may come across when learning about clinical terminologies and SNOMED CT


The specific characteristics of a CONCEPT that can be used to express RELATIONSHIPs between it and other CONCEPTs .

Example The attribute FINDING SITE indicates where in the body a disease is located – Pneumonia has Finding Site equal to Lung Structure.


A software tool that enables searching and exploring of SNOMED CT: displaying the results in an easy to understand and usable form.


A systematic arrangement of like entries based on differing characteristics, e.g. ICD10.  This is generally a method of aggregating information for statistical purposes for populations (not individuals).

 Example: ICD-10 code 410.9 - Acute Myocardial Infarction of unspecified site, episode of care unspecified


A single unit of thought or idea, with a distinct clinical meaning, to which a unique CONCEPTID has been assigned.

Example: Myocardial Infarction (disorder).


The code that uniquely identifies a CONCEPT within SNOMED CT.

 Example: For the clinical meaning of Myocardial Infarction (disorder), the ConceptId is 22298006.


A link from a single CONCEPT in SNOMED CT to its equivalent(s) in another CLASSIFICATION or TERMINOLOGY and vice-versa.

 Example: The Concept 22298006 Myocardial Infarction maps to the ICD-10 code 410.9 Acute Myocardial Infarction of unspecified site, episode of care unspecified.  Likewise it maps to X200E in CTV3 and G30.. in READ2.


Clinical Terms Version 3 (CTV3) is a terminology developed by the NHS in the late 1990’s, which subsequently became the main source of clinical data in SNOMED CT.


A five-character code allocated to a CONCEPT in CTV3.  Equivalent to the CONCEPTID in SNOMED CT.

 Example: Myocardial Infarction corresponds to the CTV3 code X200E.


A human-readable phrase or TERM associated with a SNOMED CT CONCEPT.

Note:  the words DESCRIPTION and TERM are often used interchangeably.

There are different types of descriptions used in SNOMED CT, such as FULLY SPECIFIED NAME, PREFERRED TERM and SYNONYM.


The code that uniquely identifies a DESCRIPTION within SNOMED CT.

 Example: Myocardial Infarction has a DescriptionId of 37436014.


A description that unambiguously portrays a CONCEPT.  It is not normally used in a clinical record and is always expressed in American English.

 Example:  The FSN for the Concept 22298006 is Myocardial Infarction (disorder).


An ordered organisation of CONCEPTs linked together by RELATIONSHIPs.

More general CONCEPTs appear higher in the hierarchy, with increasing levels of specialisation or granularity/detail below them.

International Edition

SNOMED CT has concepts that are common to every country’s edition; the International Edition is the part of SNOMED CT that is shared internationally.


The DESCRIPTION that is deemed to be the most clinically appropriate way of expressing a CONCEPT in a clinical record. In the UK Edition these are expressed in UK English.

Example:  The preferred term for the Concept 22298006 is Myocardial Infarction.


Qualifiers are ATTRIBUTES, which are optional relationships that may be applied to a CONCEPT to further refine its meaning in a clinical record.  In other words, adding a qualifier does not change the underlying clinical meaning of the CONCEPT but provides additional detail to the record.

Example:   Lower back pain can be qualified with the attribute SEVERITY to indicate how serious the condition is – severe lower back pain.


Also known as V2 and Read 5 byte.  Currently, this is the most commonly used clinical coding scheme in NHS Primary Care.  It is a clinical coding scheme attributed to Dr. James Read.


See READ2.


An association between two CONCEPTs.  Relationships define the structure of SNOMED CT.


A group of SNOMED CT components (normally a list of CONCEPTs) that share a specified common characteristic or use case.  Grouping CONCEPTs like this makes user selection easier by restricting what is available.

Example: a list of all procedures carried out in a podiatry clinic.


An acceptable alternative to the PREFERRED TERM as a way of expressing a CONCEPT.  

Synonyms are an alternative to the preferred term but with the same meaning. Although the same word(s) may be associated with different concepts, their clinical meaning is different.

Example 1: Dressing – within SNOMED CT, this synonym has three meanings: The act of putting on clothes, the procedure carried out on a wound, and the physical object that is placed on a wound to protect it.

Example 2: Heart Attack, Infarction of Heart and Cardiac Infarction are all Synonyms of the Concept Myocardial Infarction.


The CTV3 and READ2 equivalent to the DESCRIPTION in SNOMED CT.

Note:  the words DESCRIPTION and TERM are often used interchangeably.