Snomed CT - International Terminology

SNOMED CT, which stands for Systemised Nomenclature of Medicine - Clinical Terms, is the future of clinical coding. As electronic patient records are rolled out to Trusts across the UK, all clinicians will be involved. The purpose of this webpage is to provide an overview of the topic and explain in detail about the work the College is doing to prepare. 

On this page:

What is SNOMED CT?

In brief, SNOMED CT is an international terminology that enables clinician-entered patient details (symptoms, diagnoses, procedures and much else) to be recorded accurately at the point of patient care.
  • It allows clinicians to use terms that are familiar, clearly defined and suitable for all clinical correspondence
  • It has a hierarchical structure with general terms at the top and more specific or detailed terms below
  • This and other aspects of the structure support data analysis for secondary uses including audit and quality improvement. It will form a substantial component of the NHS electronic care record.

Why is SNOMED CT important?

SNOMED CT will provide a far more detailed and understandable record of clinical data in comparison to the coding workflows currently in practice. Presently, the majority of data is extracted from unstructured notes by clinical coders and then classified using ICD10 for diagnosis and OPCS for procedures. In future, these disease classifications will still be required, but the majority of this coding will be done using maps from SNOMED CT on a many to one basis.

For most secondary purposes that interest clinicians, such as audit, outcome monitoring, quality improvement, revalidation and research, the details contained in SNOMED CT will provide more meaningful results. It is envisaged that the widespread adoption of SNOMED CT will improve the ability to conduct high quality NHS audits, other health services evaluations, and research utilising clinician-entered data without imposing additional burden.


One of the threats to the benefits of SNOMED CT is the language used by clinicians. In paper records, terms are often loosely applied without an agreed definition. Some 'synonyms' are not actually identical; there are overlapping terms in use and terms based on an outdated understanding of pathology or genetics. The power of SNOMED CT in allowing endless variety of expression, means that is can also replicate the confusion of terms currently in use.

To counter this problem, the RCPCH is committed to developing a standardised terminology to describe the common conditions encountered in clinical practice, using the same rigour that is applied when setting up a specialist database or register. Although SNOMED CT does not currently support definitions, it is perfectly possible and in many cases desirable to produce a glossary with the definitions to support the terminology.

The Information for Quality Committee is actively seeking nominations from specialist groups to work on the terminology. Once a specialist group have agreed upon the terms they wish to use, an official SNOMED CT subset can be published by the UKTC. This may involve requesting some changes to SNOMED CT such as the addition of new terms, retirement of terms that are no longer useful and correction of terms.

Past experience suggests that about 85% of the required content is already in place. The subset can be implemented by Trust EPRs as the first point of call in a SNOMED CT search, which greatly increases the chances of inexperienced or junior clinicians locating the appropriate term. The whole of SNOMED CT will still be available to search for less common diagnoses and treatments.

Snomed CT workshop

NHS England intends to implement SNOMED CT in hospital and general practice settings as Electronic Patient Records are rolled out across the country. If the benefits to clinical practice are to be realised, it is essential that there is clinical input into specialist terminology. Representatives from clinical speciality groups attended a workshop held at RCPCH London on Thursday 14 April 2016, to discuss effective implementation of the nomenclature, the role of the Informatics committees and how we hope it will progress over the year.

Paediatric Subsets of SNOMED-CT in Practice

Across the UK, clinicians and speciality groups have begun work to create paediatric subsets for their respective specialisms.
Please see the summary below of the Disabilities Terminology Set process, Explanatory Glossary and Governance Framework, produced by Dr Karen Horridge, disability paediatrician and chair of British Academy of the Childhood Disability (BACD).
Disabilities Terminology Set (DTS)
  • Developed by clinicians across disciplines together with parent carers and terminologists, all essential to ensure the terms chosen are relevant for families and precise for recording and analysis
  • Uses SNOMED CT, the preferred coding system for the NHS, recognised internationally. This allows coding not only of health conditions, but also situations and environmental issues
  • Contains 296 terms, covering general and community paediatric health conditions at high level and disabling conditions and situations in more detail.

Explanatory Glossary of Paediatric Disability

  • Essential to underpin the DTS
  • Includes clear description of exactly what is meant by each term, the SNOMED CT code and links to any national guidance and recognised sources of further information
  • Includes suggestions for outcomes and actions for Education, Health and Care planning
  • It makes the important link between good quality data capture, recording and outomes, ensuring this is a useful tool for busy clinicians.

For further details see Disabilities Terminology Set Process, Explanatory Glossary and Governance Framework


June 2017

Mark Wardle, Consultant Neurologist, at Cardiff and Vale University Health Board, and Andy Spencer, Chair of the Informatics for Quality Committee, produced a case study of the implementation of SNOMED CT in an online clinical database in Wales.

The case study outlines how SNOMED CT has proven clinical benefits, including supporting:

  • direct patient care by making information available immediately to staff at the point of care
  • clinical governance and service provision by making aggregated data immediately available in live reporting
  • clinical research with a focus on generic and disease-specific patient outcomes.

April 2016

The RCPCH held a workshop to bring together Specialty Group Informatics leads to discuss the development of Paediatric Subsets of SNOMED-CT.  Please click the links below for resources from the event.

SNOMED-CT: Better data, better outcomes for child health - Programme(PDF, 6 Pages, 359 KB)

RCPCH Framework(PDF, 9 Pages, 144 KB)


Getting the detail right in rheumatology- Dr Ian Gaywood(PPT, 31 Slides, 1178 KB)

SNOMED CT Content - Andrew Perry(PDF, 21 Slides, 1389 KB)

SNOMED-CT Implementation, the national picture - Ian Arrowsmith (PPT, 12 Slides, 1447 KB)

Data Matters! Development of a disabilities terminology set and disabilities complexity scale - Dr Karen Horridge(PDF, 14 Slides, 2768 KB)

The Gastroenterology Project at the RCP - Professor Jonathan Brown(Ppt, 8 Slides, 2475 KB)

SNOMED-CT: Better data better outcomes - Professor John Williams(Ppt, 26 Slides, 2658 KB)

Thursday 17 March 2016

Read the latest blog post by Dr Andy Spencer, entitled 'Clinical Coding'.

Monday 29 Feburary 2016

We have recently receieved the following comment from Ian Arrowsmith of the Health and Social Care Information Centre (HSCIC):

“The UK Terminology Centre (UKTC) of the HSCIC is very pleased to work with the RCPCH to assist with the development of specialty specific SNOMED CT content, subsets and definitions. The support of the College is a huge enabler to the wide scale deployment of standards which will improve interoperability, and of course, the care delivered to every child in the UK.”

Ian Arrowsmith, Head of SNOMED CT Implementation, Health and Social Care Information Centre


Useful Websites
Useful Documents
Electronic Patient Records (PDF, 7 pages, 490 KB)

If you have any queries or comments please contact