SNOMED CT: An Introduction — Part 1

SNOMED CT: An Introduction — Part 1

SNOMED CT (Systematised Nomenclature of Medicine — Clinical Terms) is a standardised, multilingual vocabulary of clinical healthcare terminology used by physicians and other health care providers for the electronic exchange of clinical health information.


To use coding in healthcare, a number of things are required. One requirement is a comprehensive library of clinical terms, a terminology, which SNOMED CT provides. It is a standardised terminology, where every clinical term is represented as a concept that includes every synonym in every language. This means that clinical notes do not lose their meaning and are accurately communicated across multiple care settings from a GP to a hospital.

Patient notes contain large amounts of text and people express the same thing in different ways. So when clinicians search for something, they would have to search for every possible term.

For example, a ‘red blood cell’ can also be noted down as ‘erythrocyte’ or simply ‘RBC’. So a doctor searching for `RBC` when the patient record has `erythroctye` could miss relevant records.

SNOMED CT solves this problem by returning the matching records, even if they have any alternative word for RBC.

Another requirement is having an electronic patient health record helping clinicians to communicate and access relevant information about the patient. If this clinical information was stored and easily retrieved, it removes the need for taking multiple patient histories and relying on the information the patient provides. For this, a common language for clinical data, understood by both humans and computers is required. SNOMED CT allows clinical data to be recorded in this way. Clinicians can also reuse this clinical data for making real-time decisions.

Therefore, when implemented into software, SNOMED CT displays comprehensive and reliable clinically relevant coded patient data as part of their electronic patient record that follows them to every care setting.

How it works

To make clinical terms understandable by both humans and computers, SNOMED CT represents medicine in a very specific way.

  • SNOMED CT has concepts, each one for a discrete clinical idea.
  • Each concept can have multiple descriptions, in different languages or dialects.
  • One of these descriptions is marked as the preferred term.
  • The coverage of SNOMED CT is very extensive as well as granular
  • All concepts are arranged in a hierarchy so that the data can be viewed at any level of granularity.
  • There is an independent system of classification (poly-hierarchy) not relying on code structures

SNOMED CT has been selected and approved to be the terminology used by the NHS in England. It is the most comprehensive international terminology currently available and can be used across all care settings and all clinical domains.

As we move to more integrated care records with information following patients, it is important that information is consistent and transferable within and across all the healthcare settings where a patient may be treated; the use of coded information supports recording in a consistent and transferrable way.

In the next part of this article, we will explore Interoperability, NHS Digital, and what Termlex is doing to help with the adoption and implementation of SNOMED CT in the UK. Stay tuned!


Want to read more? Check out the next parts of this article below!

We hope you found this introduction to SNOMED CT interesting. If you have any questions or feedback, please shoot us an email at [email protected].Part 2 –
Part 3 –

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