MeSH - Medical Subject Headings
The MeSH (Medical Subject Headings) is a polyhierarchical, concept-based thesaurus (keyword register) for the cataloguing of book and media collections, indexing of databases and creation of search profiles.
MEDLARS Centers as national partners for the MeSH
The MeSH is published by the NLM. The NLM collaborates worldwide with national institutions in foreign countries, which then act as MEDLARS Centers to ensure access to translations of the MeSH for that country. The NLM register of international MEDLARS Centers gives you more information on the distribution of the MeSH in other languages.
Former DIMDI is the MEDLARS Center for Germany.
Original version vs. German translation
In order to preserve the character of the thesaurus and the keyword register, former DIMDI translated the MeSH descriptors into German according to the American template.
For the German version, the main headings from the original version has been translated 1:1. The main headings has been supplemented with the common synonyms used in German-speaking countries. The fact that the number of German synonyms does not correspond to those in English is due to the different language areas and use.
The original version from the NLM includes a prefix with a multitude of annotations, references and definitions for the individual descriptors. This part is not included in the German translation. Therefore, when using the German MeSH intensively for cataloguing, indexing and creating search profiles, it is important to also always refer to the English edition for additional information.
The NLM updates the MeSH on an annual basis. Former DIMDI translated the update into German until 2018. This is a bilingual version, since the corresponding English equivalents are included in addition to the German descriptors.
The version 2019 of the MeSH contains the following numbers of descriptors:
- 29.351 German Main Headings (preferred terms)
- 29.351 English Main Headings
- 68.789 German Entry Terms (synonyms)
- 214.879 English Entry Terms
Development and significance of the MeSH
The MeSH initially emerged from the keyword register of the Index Medicus Bibliography. The National Library of Medicine (NLM) in the USA published these by since more than 100 years. The precursor of MeSH, the Subject Heading Authority List, was published by the NLM for the first time in 1954. In 1960, a new, fundamentally revised version was published as the Medical Subject Headings.
Concepts replace descriptors
Towards the end of the year 1980, the growing terminology and the desire to improve the representation of the relationships among the MeSH terms led to the conversion of the descriptor-based structure to the concept-based structure and the development of a concept-based maintenance system for the MeSH terminology. Not visible to the user, the new structure enables a better representation of the relationships among the terms and easier updating of the translations. Furthermore, the restructuring facilitated the integration of the MeSH into the Metathesaurus Unified Medical Language System (UMLS).
You can find details on the conversion in the following publication: Nelson, Stuart, J.; Schopen, Michael; Schulmann, Jacque-Lynne; Arliuk, Natalie. An Interlingual Database of MeSH Translations. 8th International Conference on Medical Librarianship; 2000 Jil 4; London, UK.
In 2004, the MeSH was issued for the first time in a new software environment, which enables the maintenance of all the MeSH translations online via Internet on the computer of the NLM. However, this translation tool of the NLM is no longer available since 2019.
MeSH as the central component of the UMLS
MeSH also gained significance through the development of the UMLS. In addition to many other (bio)medical terminologies, this metathesaurus also includes MeSH in several languages.
Unified Medical Language System (UMLS)
MEDLINE – Source and User of the MeSH
MeSH initially emerged from the keyword register of the Index Medicus Bibliography. The MEDLINE literature documentation system from the NLM is its successor, with users all over the world. The MEDLINE database is available with different hosts and also uses the MeSH descriptors.
Application example: HONselect search machine
HONselect is a search machine from the Health On The Net Foundation (Geneva). You can, among other things, display the different levels of the MeSH Tree Structures - a hierarchical classification of the key words - in German and in other languages.