This article describes the medical indexing system. For other uses see mesh (disambiguation)
Medical Subject Headings (MeSH) are the controlled vocabulary now used to index biomedical articles for the National Library of Medicine's MEDLINE data base.  They are arranged as a hierarchical database with extensive cross-linking. There is a convenient browser for the MeSH vocabulary, which is often used as a dictionary of terms and a thesaurus or cross-index of related terms.
These headings preceded medical literature data bases, and were used as the indexing terms for a printed series of volumes, Index Medicus.
MeSH, while extensively used, is not frozen in time. New medical terms are constantly added, but MeSH is part of a larger research project, the Unified Medical Language System (ULMS), which is intended to be compatible with semantic web and other more modern information models. ULMS will incorporate MeSH, but also many other systems including:
- Logical Observation Identifier Names and Codes (LOINC)
- Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT)