Medical Subject Headings (MeSH) is a comprehensive, controlled vocabulary produced by the National Library of Medicine. It is used to index, catalog, and search for articles and books in the life sciences.
MeSH is used by MEDLINE/PubMed, the NLM Catalog, and other NLM databases as a thesaurus that facilitates searching. It is available free of charge online. The ClinicalTrials.gov registry also uses MeSH to classify which diseases are studied by trials registered in ClinicalTrials.
The MeSH vocabulary is regularly updated and contains the following main types of terms:
- Headings, also known as descriptors, characterize the article’s subject matter. Definitions, links to related headings, and a list of similar terms (known as entry terms) typically accompany headings.
- Subheadings, also called qualifiers, more completely describe a particular aspect of a subject and make it possible to group documents.
- Publication types refer to the type of material the article represents.
- Supplementary concept records (SCRs) describe substances such as chemical products and drugs that are not included in the MeSH terms.