Medical Subject Headings (MeSH) is a hierarchically-organized terminology for indexing and cataloging of biomedical information. It is used for the indexing of PubMed and other NLM databases. Please see the Terms and Conditions for more information regarding the use and re-use of MeSH. NLM produces Medical Subject Headings XML, ASCII, MARC 21 and RDF formats.

Updates to the data files are made according to the following schedule:

MeSH XML
MeSH Descriptor files updated annually
MeSH Qualifier files updated annually
MeSH Supplemental Concept Records (SCR) updated daily (Monday - Friday)

MeSH ASCII
MeSH Descriptor files updated annually
MeSH Qualifier files updated annually
MeSH Supplemental Concept Records (SCR) updated daily (Monday - Friday)

MeSH MARC21
All files posted monthly

MeSH RDF
All files posted daily (Monday - Friday)

A system for producing indexing recommendations to assist in the indexing process at NLM. Currently provides indexing recommendations to more than 100 journals based on the NLM Medical Subject Headings (MeSH) vocabulary.

MTI is the main product of the Indexing Initiative project and has been providing indexing recommendations based on the Medical Subject Headings (MeSH®) vocabulary since 2002. In 2011, NLM expanded MTI's role by designating it as the first-line indexer (MTIFL) for a few journals; today the MTIFL workflow includes over 350 journals and continues to increase. The close collaboration of the NLM Index Section, Lister Hill National Center for Biomedical Communications, and Office of Computer & Communications Systems continues to expand and refine the ability of MTI to provide assistance to the indexers.

PubMed is a free resource supporting the search and retrieval of biomedical and life sciences literature with the aim of improving health–both globally and personally.

The PubMed database contains citations and abstracts of biomedical literature. It does not include full text journal articles; however, links to the full text are often present when available from other sources, such as the publisher's website or PubMed Central (PMC).

See the PubMed User Guide for more information. https://pubmed.ncbi.nlm.nih.gov/help/

MedlinePlus is the National Institutes of Health's Web site for patients and their families and friends. Produced by the National Library of Medicine, the world’s largest medical library, it brings you information about diseases, conditions, and wellness issues in language you can understand. MedlinePlus offers reliable, up-to-date health information, anytime, anywhere, for free.

This dataset includes all newly added MeSH Main Headings for 2023. Headings play a central role in MeSH vocabulary as a unit of Indexing and retrieval. With the exception of Class 3 Descriptors, all descriptors are organized into a numbered tree structure or hierarchy that allows users to browse in a orderly fashion from broader to narrower topics. Scope Notes provide a concise summary describing the meaning and scope of the MeSH Descriptor.

Publication Types (Publication Characteristics) are Descriptors that indicate what an indexed item is, (i.e., its genre, rather than what it is about - for example, Historical Article). They may include Publication Components, such as Charts; Publication Formats, such as Editorial; and Study Characteristics, such as Clinical Trial.

They function as metadata, rather than being about the content. These records are searchable in PubMed as Publication Type [PT], and the terms in MEDLINE records are labeled as "PT" or rather than "MH" or . They are listed in category V of the MeSH Tree Structures.

An overview of Year-End Processing (YEP) for MeSH/MEDLINE, including update reports

MeSH on Demand identifies MeSH Terms in your text using the NLM Medical Text Indexer (MTI) program. After processing, MeSH on Demand returns a list of MeSH Terms relevant to your text as well as a list of related articles from PubMed.

Working with partners across NIH, led by NIMHD and the NLM OBSSR-Behavioral Ontology Working Group, MeSH on November 29, 2022 added Federally recognized American Indian and Alaskan Native (AI/AN) tribal names and ethnic/ethnolinguistic minority terms as newly created type 5 SCR designated as “Population Groups”. These minority names (1,700+ terms) were mapped and reviewed by subject matter experts and scientists within NIH and from outside including Network of the National Library of Medicine members.

Structure: All type 5 SCRs have common fields
1. CC=5 Population Group
2. ST=T098 Population Groups
3. HM= At least one HM is to an MH under Population Groups [M01.686]
4. TH= NIMHD(2023)

Listed below are MeSH Topical Qualifiers listed by Name, Abbreviation, and Short Form. Each Qualifier is defined by a Scope Note that provides guidance on how it should be used.