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PubMed Tutorial from The Levy Library: Why Do a MeSH Search?

Consider a MeSH Search If...

You need more precise results in a subject search. For example:

1. Your basic search results are too large and not focused on your main concepts.

In a basic search, your search terms (and the synonyms found by Automatic Term Mapping) will be found in all the fields of a record, including ones where your search term only mentioned in the abstract. A MeSH search is a type of field search, and like any search using field qualifiers, it will retrieve fewer results than a similar text word search. More importantly, in a MeSH search, PubMed restricts your results to articles indexed with a subject heading for your topic

2. A large amount of literature has been published on your topic.

A MeSH search enables you to restrict your search to Major Topic Headings only. This allows you to retrieve articles where your topic is a major point discussed, rather than a secondary focus or finding.

3. You need to disambiguate a search word or phrase. 

  • Example: Searching with the word "aids" retrieves articles on AIDS virus, as well as articles on hearing aids, audiovisual aids, clinical aids, teaching aids, etc. Using the MeSH term for AIDS: Acquired Immunodeficiency Syndrome [MeSH] will limit your retrieval to the relevant subject.
  • Example: Searching with the word expression retrieves articles about gene expression, but also facial expression, verbal expression, etc. Using the MeSH term "Gene Expression" [MeSH] will disambiguate your search and limit your retrieval to the relevant subject.

Consider Using MeSH Subheadings if...

If you need to focus on a specific aspect of a topic, consider using a MeSH subheading.

MEDLINE uses a combination of MeSH headings and coordinated subheadings to describe a concept as specifically as possible. 
Use MeSH with subheadings to target your retrieval on one aspect of a larger topic such as "Etiology of Sickle Cell Anemia", "Genetics of Turner Syndrome" or "Biosynthesis of RNA"

Tip: When your topic contains the word "of", consider selecting MeSH and MeSH subheadings for your search.

Although the subheading field can be searched separately, subheadings are usually "attached" to MeSH descriptors to describe an aspect of that topic. To directly attach MeSH Subheadings, you must either use the MeSH Database or use the format MeSH Term/Subheading, e.g., neoplasms/diet therapy.