Medical Subject Headings

Files Available to Download

Download of any of the full data files requires the completion of an online Memorandum of Understanding.

2013 MeSH
- These formatted versions of the entire MeSH vocabulary are available to download. For best results in downloading, use of a graphical interface is recommended.
  - 2013 MeSH in XML format. MeSH descriptors and qualifiers, and Supplementary Concept Records (formerly Supplementary Chemical Records) in XML format. Files are updated weekly. Supplementary records are compatible with 2013 MeSH descriptors. Descriptor file is 292MB in size, uncompressed. Compressed file is 15MB.
  - 2013 MeSH in ASCII format. MeSH descriptors and qualifiers, and Supplementary Concept Records (formerly Supplementary Chemical Records), in ASCII format. Files are updated weekly. The descriptor file is 28MB in size and may take more than 30 minutes to download using a connection 2400 bps or slower. Postings data in descriptor and qualifier records reflect updates in citation files through the October, 2000 entry month.
    Note that subfield separator for descriptor entry terms has been changed from a colon to a bar (|) in order to make it easier to parse terms containing colons.
    - Sample Text
    - About ASCII MeSH
  - 2013 MeSH Trees. MeSH main headings with the tree numbers that place the heading in a hierarchical arrangement. Sorted by tree number. ASCII format. [2.1MB]
    - Sample Text
    - About MeSH Trees
  - 2013 MeSH in MARC format. MeSH vocabulary data in the USMARC authority format.
- These files are also available for 2013 MeSH:
  - Pharmacologic Actions - 2013.
    - Substances with a given Pharmacologic Action - 2013. Forthcoming.
  - New Headings with Scope Notes - 2013. Main headings that are new for 2013 with scope notes (definitions), cross-references, and other information.
  - MeSH Replaced Headings - 2013. Main headings that have changed form for 2013 or have been deleted.
  - 2013 Descriptors - preferred term only
  - MeSH MN (tree number) Changes - 2013. Main headings in which there has been a change in the MN (MeSH tree Number) for 2013.
2012 MeSH in XML format. MeSH descriptors and qualifiers, and Supplementary Concept Records (formerly Supplementary Chemical Records) in XML format. Files are updated weekly. Supplementary records are compatible with 2012 MeSH descriptors. Descriptor file is 288MB in size, uncompressed. Compressed file is 15MB.
2012 MeSH in ASCII format. MeSH descriptors and qualifiers, and Supplementary Concept Records (formerly Supplementary Chemical Records), in ASCII format. Files are updated weekly. The descriptor file is 28MB in size and may take more than 30 minutes to download using a connection 2400 bps or slower. Postings data in descriptor and qualifier records reflect updates in citation files through the October, 2000 entry month.
Note that subfield separator for descriptor entry terms has been changed from a colon to a bar (|) in order to make it easier to parse terms containing colons.
- Sample Text
- About ASCII MeSH
2012 MeSH Trees. MeSH main headings with the tree numbers that place the heading in a hierarchical arrangement. Sorted by tree number. ASCII format. [2.1MB]
- Sample Text
- About MeSH Trees
2012 MeSH in MARC format. MeSH vocabulary data in the USMARC authority format.
This file is also available for 2012 MeSH:
- Substances with a given Pharmacologic Action - 2012.

2011 MeSH
- 2011 MeSH in MARC format. MeSH vocabulary data in the USMARC authority format.
2004 MeSH
- 2004 MeSH files for TREC (Text REtrieval Conference) Genomics track. For use by the TREC community with the 2004 MEDLINE/PubMed Baseline.
MeSH ELHILL Format Document (PDF format): This is a description of the MeSH data elements in the ELHILL Unit Record Format (EURF), NLM's former format for distributing MeSH on tape. Most elements are common to both the ASCII and EURF MeSH formats and so the description of MeSH data in the EUR format may be of interest to those downloading the ASCII MeSH files from the Web.

For questions concerning distribution, format, etc., contact:: Jacque-Lynne Schulman; Medical Subject Headings; Telephone: 301-496-1495; FAX: 301-402-2002; email: schulman@nlm.nih.gov