Embase is a bibliographic database produced by Elsevier B.V. Embase indexing is based upon the Elsevier Life Science Thesaurus Emtree, a hierarchically structured, controlled vocabulary for biomedicine and related life sciences. More than twice as large as MEDLINE's thesaurus MeSH and including all MeSH terms, Emtree opens up access to the literature via tens of thousands of biomedical terms and synonyms. Consistent descriptions of biomedical information offer indexers a comprehensive vocabulary to describe the content of biomedical data. For database users, it facilitates comprehensive searching and precision retrieval.