UMLS
The Unified Medical Language System® (UMLS®) is a set of files and software bringing together health and biomedical vocabularies and standards to enable interoperability between computer systems. The UMLS integrates and distributes key terminology, classification and coding standards, and associated resources to promote creation of more effective and interoperable biomedical information systems and services, including electronic health records. Software developers can use UMLS to enhance or develop applications, such as electronic health records, classification tools, dictionaries and language translators. Use of UMLS allows end users to view codes, synonyms, and definitions used terminologies such as Common Procedural Terminology and International Classification of Diseases-10th Revision-Clinical Modification and relationships between concepts. Access requires a free UMLS License.