Content | |
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Description | Medical Subject Headings |
Data types captured |
controlled vocabulary |
Contact | |
Research center |
United States National Library of Medicine National Center for Biotechnology Information |
Laboratory | United States National Library of Medicine |
Authors | F B Rogers |
Primary citation | PMID 13982385 |
Access | |
Website | https://www.nlm.nih.gov/mesh/ |
Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences; it serves as a thesaurus that facilitates searching. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed article database and by NLM's catalog of book holdings. MeSH is also used by ClinicalTrials.gov registry to classify which diseases are studied by trials registered in ClinicalTrials.gov.
MeSH was introduced in 1960, with the NLM's own index catalogue and the subject headings of the Quarterly Cumulative Index Medicus (1940 edition) as precursors. The yearly printed version of MeSH was discontinued in 2007 and MeSH is now available online only. It can be browsed and downloaded free of charge through PubMed. Originally in English, MeSH has been translated into numerous other languages and allows retrieval of documents from different languages.
The 2009 version of MeSH contains a total of 25,186 subject headings, also known as descriptors. Most of these are accompanied by a short description or definition, links to related descriptors, and a list of synonyms or very similar terms (known as entry terms). These additional information and the hierarchical structure (see below) make the MeSH essentially a thesaurus, rather than a plain subject headings list.
The descriptors or subject headings are arranged in a hierarchy. A given descriptor may appear at several locations in the hierarchical tree. The tree locations carry systematic labels known as tree numbers, and consequently one descriptor can carry several tree numbers. For example, the descriptor "Digestive System Neoplasms" has the tree numbers C06.301 and C04.588.274; C stands for Diseases, C06 for Digestive System Diseases and C06.301 for Digestive System Neoplasms; C04 for Neoplasms, C04.588 for Neoplasms By Site, and C04.588.274 also for Digestive System Neoplasms. The tree numbers of a given descriptor are subject to change as MeSH is updated. Every descriptor also carries a unique alphanumerical ID that will not change.