Several tools and resources have been developed by the National Library of Medicine to facilitate the use of terminologies in health care research and practice. These tools are used for a variety of purposes including exploring or browsing terms, mapping between terminologies, processing text, aggregating terminologies, and access. See the NLM Health IT page for details.

A "map" between terminologies in healthcare refers to the process of linking or translating concepts from one coding system or terminology to another. This is crucial in healthcare because different organizations, systems, and applications often use different terminologies to describe the same clinical concepts. Mapping ensures that data can be consistently understood and used across various systems, enabling interoperability, data integration, and accurate clinical decision-making.

The Unified Medical Language System (UMLS) is the NLM’s key tool for mapping between terminologies, so we’ll start our exploration of NLM terminology tools here.