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Medical Subject Headings (MeSH)

What is MeSH?

MeSH is the controlled vocabulary developed by the National Library of Medicine for indexing the literature of medicine. MeSH is the vocabulary of MEDLINE & PubMed, as well as the online catalog of the Health Sciences Library.

A controlled vocabulary is designed to make searching easier, by taking the guesswork out of choosing the terms one needs to enter into a search. A controlled vocabulary identifies the appropriate term to use when looking for information on a concept which can be expressed in several ways.

For instance, every article about cancer in MEDLINE is assigned the MeSH heading, "Neoplasms", and articles about breast cancer are assigned, "Breast Neoplasms". Articles about teenagers, are assigned the MeSH heading, "Adolescent". One needn't think up every possible synonym.

There are nearly 22,000 terms, arranged hierarchically, in the MeSH vocabulary. Every processed record in MEDLINE/PubMed has several MeSH terms assigned to it which describe the contents of the indexed article. The searcher should take advantage of these terms in constructing a search strategy.

How do I find the MeSH term(s) to use to find articles on a particular topic?

Most MEDLINE interfaces -- whether Ovid, WebSPIRS or PubMed -- have a built in thesaurus tool to help identify MeSH terms.

In PubMed:

1. Use PubMed's thesaurus tool, the MeSH Database or
2. Execute a keyword (or free-text) search and look at the MeSH headings on a particularly good record -- by displaying the article in Citation format. Then use that term or a combination of those terms to find similar articles.
3. Execute a keyword (or free-text) search then use the Details button to see how PubMed has translated your search. PubMed uses automatic term mapping to identify the MeSH headings that best map your search.

In addition, the Library has several copies of the print MeSH tools in the Reference area.

How do I use the MeSH Database?

1. Select MeSH Database from the blue left-hand side bar.
2. Type a term into the query box. Select the best heading(s) from the list presented by clicking on the box next to the heading and either:
   1. send to search by clicking on the "Send to" button or
   2. expand a heading by clicking on the heading name and:
      • Click on the box next to the MeSH heading
      • Decide which subheadings, if any, you would like to use and select by clicking on the boxes.
      • Decide whether you would like this MeSH term to be the major focus of your search and if so click to Restrict...
      • Decide whether you would like to also search the more specific terms which come under this term in the MeSH hierarchy. If you would not, click, "Do not explode this term."
3. Click "Send to" button to send the term to the MeSH Database search box.
4. Then either repeat the above process to add more MeSH terms or click on "Search PubMed" to execute the search.

M. Ascher 11/23/04