UMLS Tools
Many users of the UMLS, both at NLM and elsewhere, have developed different tools that can be used with the UMLS Knowledge Sources. Here is a list of tools that are open for use by UMLS users. Items with Image indicates license agreement is required require a signed license agreement prior to use and can be accessed via the UMLS Knowledge Source Server (UMLSKS).

MetamorphoSys Information
Lexical Tools
MeSH Browser
Sample Load Scripts and Data Model
Metathesaurus String Properties Image indicating license agreement is required

A vector of properties computed for each English string in the Metathesaurus. These properties help select Metathesaurus strings that are suitable for Natural Language Processing (NLP) applications.
Semantic Navigator Image indicating license agreement is required

Experimental knowledge exploration tool for the UMLS. It displays the semantic space surrounding an arbitrary UMLS concept. Clicking on any concept dynamically generates a new display in which the entered concept becomes the center of the new semantic space.
Semantic Groups Image indicating license agreement is required

A coarse-grained set of semantic type groupings designed to reduce the complexity in the UMLS Metathesaurus. The 15 semantic groups provide a partition of the UMLS Metathesaurus for 99.5% of the concepts.
MetaMap & MetaMap Transfer (MMTx) Image indicating license agreement is required


MetaMap is a highly configurable program developed at the National Library of Medicine (NLM) to map biomedical text to the Metathesaurus or, equivalently, to discover Metathesaurus concepts referred to in text. MetaMap uses a knowledge intensive approach based on symbolic, natural language processing (NLP) and computational linguistic techniques.

MMTx is an effort to make the MetaMap program available to biomedical researchers in a generic, configurable environment.With this software, text is processed through a series of modules. First it is parsed into components including sentences, paragraphs, phrases, lexical elements and tokens. Variants are generated from the resulting phrases. Candidate concepts from the UMLS Metathesaurus are retrieved and evaluated against the phrases. The best of the candidates are organized into a final mapping in such a way as to best cover the text.

Last reviewed: 25 November 2008
Last updated: 25 November 2008
First published: 26 March 2004
Metadata| Permanence level: Permanence Not Guaranteed