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MeSH Trees 2016. Documentation and Availability

1. MeSH Trees

The National Library of Medicine makes a hierarchical arrangement of its Medical Subject Headings (MeSH) with their associated tree numbers available in an electronic file.

These hierarchical data are collectively known as the MeSH Tree Structures. They are updated annually and users of the data are encouraged to obtain the new year's data annually.

The MeSH Tree Structures data represent a part of NLM's MeSH data. They do not include, for example, cross-references, scope notes, or subheadings. These data are available as MeSH in MARC format, and ASCII MeSH. ASCII MeSH also contains Supplementary Concept Records (formerly Supplementary Chemical Records). Also, two Descriptors do not have Tree Numbers: "Male" and "Female".

2. Restrictions on use

No license is required, however, use of the trees file data is subject to conditions which are detailed in the Memorandum of Understanding.

3. Availability

MeSH Descriptors and Qualifiers are only published electronically, including MeSH Trees.

MeSH Trees are available online in the MeSH Browser. 

4. Contact

For questions concerning distribution, format, etc., contact:

Jacque-Lynne Schulman
Medical Subject Headings
voice: 301-594-2091