Unified Medical Language System® (UMLS®) Basics

Searching with the UMLS Terminology Services

The UMLS Terminology Services offers users many options for searching the UMLS Knowledge Sources.

Metathesaurus Searching
Users can search for a concept by entering a term name, a Concept Unique Identifier (CUI), or a code. Users can further limit the search by selecting the release and the source. A third search option, Search Type, restricts parameters to an approximate or exact match, allows users to left or right truncate a word, or to search by a normalized string or word.  All options search the complete Metathesaurus. There is no search option designed to search a subset stored on a user’s computer.

All search options return the same information:

• Concept
• CUI (Concept Unique Identifier)
• Semantic Type(s)
• Definition (if provided)
• Atoms
• Contexts
• Concept Relations

Semantic Network Browsing
Users can select the semantic type or relation from two menus to view the semantic record for each semantic type or relation.

Semantic records include the following information, where applicable:

• Definition
• Properties
• Parents
• Children
• Relations
• Inverse Relations
• Inherited Relations
• Inverse Inherited Relations

Users can also browse the semantic types and relations by selecting 'Tree' tab. This view allows users to expand the semantic type adn relations hierarchies to view the semantic record for each item.

SNOMED CT® Searching
Users can search for and display SNOMED CT content, as included in the Metathesaurus. Users can search by SNOMED CT term, SNOMED CT ConceptID, or SNOMED CT DescriptionID.

Users can also navigate the SNOMED CT hierarchy from its topmost "SNOMED CT Concept" through the 19 SNOMED CT main categories to the individual concepts organized within them.

Developer Resources
Users can remotely query and retrieve data from the Metathesaurus using the UTS Web services API.

The UTS also 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.