Module 1: Foundations of MeSH in MEDLINE®

What is MeSH?

Medical Subject Headings (MeSH) is the National Library of Medicine’s controlled vocabulary thesaurus that gives uniformity and consistency to the indexing and cataloging of biomedical literature. It connects all the different ways to express a concept, such as “cancer."

MeSH is a distinctive feature of MEDLINE, NLM’s premiere bibliographic database for biomedical literature. MEDLINE is directly searchable from PubMed. PubMed also includes citations from PubMed Central (PMC) and the National Center for Biotechnology Information (NCBI) Bookshelf. Only those citations featured in MEDLINE, however, are indexed with MeSH terms.

MeSH terms are revised annually to reflect changes in the biomedical literature. You can check out the most recent updates on the MeSH “What’s New” page.

MEDLINE, PMC, and Bookshelf logos pointing to PubMed logo

Who uses MeSH?

  • Searchers of MEDLINE/PubMed, library catalogs, and other databases use MeSH to assist with subject searching.
  • NLM staff apply MeSH to describe the subject content of journal articles for MEDLINE and update the MeSH vocabulary annually.
  • Catalogers use MeSH to describe books and audiovisuals in the NLM and other medical library collections.