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Fact Sheet
UMLS® Terminology Services

Background

The Unified Medical Language System® (UMLS®) integrates and distributes biomedical terminology, classification, and coding standards. It enables the creation of interoperable electronic health records and biomedical information systems. The UMLS provides data for system developers as well as search and retrieval functions for less technical users.

The UMLS includes three Knowledge Sources (Metathesaurus®, Semantic Network, and SPECIALIST Lexicon).

UMLS® Terminology Services (UTS)

The UMLS Terminology Services (UTS) replaces the UMLS Knowledge Source Server (UMLSKS) with new features and improved access to UMLS and other NLM terminology resources. The UMLSKS is the retired browser for the Knowledge Sources.

The UTS provides online access to the Knowledge Sources and other UMLS related resources. The UTS allows single sign-on access to all UMLS resources: terminology browsers, file downloads, reporting tools, and user profile management.

The UTS includes updated versions of the Metathesaurus and Semantic Network browsers from the retired UMLSKS. Tree browsers are incorporated into the updated browsers. The UTS also incorporates a new browser: the SNOMED CT® Browser.

You must have an active UMLS Metathesaurus License to access the UTS. For instructions on requesting a license and accessing the UTS, see How to License and Access the Unified Medical Language System® (UMLS®) Data.

Metathesaurus® Browser

The Metathesaurus Search tab allows you to search the Metathesaurus by Term, Concept Unique Identifier (CUI) or Code. You can request information about particular Metathesaurus concepts, such as definitions, semantic types, related concepts, hierarchical details, and co-occurrence information. Searches can be restricted to a particular source vocabulary.

The Metathesaurus Tree tab allows you to navigate the hierarchy of a selected source vocabulary in order to browse both its content and structure. Note: Some source vocabularies in the UMLS Metathesaurus are not organized into a hierarchical arrangement and cannot be browsed using the Metathesaurus Tree Browser.

Semantic Network Browser

The Semantic Network List tab allows you to browse the Semantic Network for specific semantic types and semantic relations. Information in the Semantic Network can be queried in terms of two semantic types and the relationship between them.

The Semantic Network Tree tab shows the hierarchical representation of the semantic types and semantic relations that comprise the Semantic Network.

SNOMED CT® Browser

The SNOMED CT Search tab enables you to search for and display SNOMED CT content, as included in the Metathesaurus. You may search by SNOMED CT term, SNOMED CT ConceptID, or SNOMED CT DescriptionID.

The SNOMED CT Tree tab allows you to navigate the SNOMED CT hierarchy from its topmost "SNOMED CT Concept" and through the 19 SNOMED CT main categories to the individual concepts organized within them.

SPECIALIST Lexicon and Lexical Tools

The SPECIALIST Lexicon is accessible through the Downloads menu of the UTS.

The SPECIALIST NLP Tools are accessible through the Resources menu of the UTS.

Downloads

Several NLM terminology resources, including the Knowledge Sources, are accessible through the Downloads menu of the UTS.

Developer Resources

The UTS includes a Web services API to remotely query and retrieve data from the Metathesaurus.

The UTS includes a RESTful interface that allows application developers to verify that users have an active license code. Application developers must be authorized distributors of UMLS data to use this service.

More information on these services is available under Technical in the Documentation menu of the UTS.

Other Resources

The Resources menu of the UTS provides links to additional NLM terminology resources, including MetaMap and RxNav.

Documentation

The Documentation menu of the UTS provides links for General and Technical documentation. Use General Documentation to learn more about the UMLS, RxNorm, and SNOMED CT. Use Technical Documentation to learn more about developer resources, source documentation, and database queries.


A complete list of NLM Factsheets is available at:
(alphabetical list): http://www.nlm.nih.gov/pubs/factsheets/factsheets.html
(subject list): http://www.nlm.nih.gov/pubs/factsheets/factsubj.html

Or write to:

FACT SHEETS
Office of Communications and Public Liaison
National Library of Medicine
8600 Rockville Pike
Bethesda, MD 20894

Phone: (301) 496-6308
Fax: (301) 496-4450
email: publicinfo@nlm.nih.gov