Medical Subject Headings (MeSH)

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In this tutorial you will learn how to use Medical Subject Headings (MeSH) when searching the PubMed / Medline database.

Acknowledgments: We gratefully acknowledge our use of the National Library of Medicine's PubMed online training materials in developing this tutorial.


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What is MeSH?

1 of 2The PubMed / Medline database uses a controlled vocabulary thesaurus known as Medical Subject Headings (MeSH®).

The MeSH thesaurus imposes uniformity and consistency on the indexing of biomedical literature.

Using terms from MeSH in your PubMed database searches can improve your search results by helping you to identify

  • the most specific terms to focus your results


  • related terms to broaden your results.

On the page to your right, under More Resources, select NLM MeSH Homepage.

What is MeSH?

2 of 2

On the NLM MeSH Homepage, look for the MeSH Fact Sheet, under All About MeSH.

Review the first section (The Thesaurus) of the Fact Sheet.

How many descriptors are in the MeSH?

MeSH Headings

The MeSH vocabulary includes four types of terms:

  • Headings
  • Subheadings
  • Supplementary Concepts
  • Publication Characteristics

Indexing staff (indexers) at the National Library of Medicine (NLM) examine journal articles and assign the most specific MeSH headings that appropriately describe the concepts discussed in the paper.

  • The indexer will assign as many MeSH headings as appropriate to cover the topics of the article (generally 5 to 15).
  • When there is no specific heading for a concept, the indexer will use the closest general heading available.

Examples of headings include:

  • Child Nutrition Disorders
  • Nutrition Assessment
  • Parenteral Nutrition

MeSH Subheadings

To further describe a particular aspect of a MeSH concept, indexers can also assign Subheadings.

Examples of Subheadings include:

  • diagnosis
  • surgery
  • metabolism
  • pathology

You will see a subheading in combination with a heading. For example:

Anorexia Nervosa/diagnosis

MeSH Supplementary Concepts, Publication Characteristics and Major Points

In addition to assigning MeSH terms that describe the topic of the article, the indexer provides terms that reflect:
  • characteristics of the group being studied (e.g., the age group, human or other animal, male or female)
  • pharmacologic actions
  • publication type e.g., Clinical Trials, Editorial, Review

The MeSH terms that reflect the major points of the article are marked with an asterisk (*).

Search the MeSH database

Now that you know something about what MeSH is and how it is created and organized, let's try it out!

Enter the term diabetes in the search box at the top of the screen on the right. (Note: The default is set to search MeSH.)

As you type in the term, the database may show a drop-down list of terms that have the word you are typing. You can turn this feature off by clicking on "Turn Off" at the bottom of the drop-down box.

Click "Search". This will bring up MeSH terms that include the word diabetes.

How many MeSH records are there in the search results?

Examine a MeSH record

From the search results screen for diabetes, click on the record for Diabetes Mellitus,Type 2.

This will show the subheadings that are in the hierarchy under that broad subject heading.

Scroll down and review the rest of the MeSH record for Diabetes Mellitus, Type 2. Look for the "See also" section.

In the "See also" section, which disease categories does "diabetes mellitus, type 2" appear under?

Choose a subheading and search PubMed

Scroll back up to the top of the record for the term Diabetes Mellitus, Type 2.

Choose "diet therapy" from the list of subheadings.

Also select "Restrict to MeSH Major Topic" (under the list of subheadings).

On the right side of the page, locate the PubMed Search Builder box. Click on "Add to search builder" and then "Search PubMed".

How many results (article records) are retrieved by this search?

Refine your results and review MeSH terms for an article

At the top of the screen showing your search results, click on "Limits".

Select "Type of Article - Meta-Analysis" and "Languages - English".

Scroll down and click "Search".

Click on the record for the article by K. Esposito et al.

"Prevention of type 2 diabetes by dietary patterns: a systematic review of prospective studies and meta-analysis."

Examine the Publication Types and MeSH terms for this article. (Click on the plus (+) sign under the abstract.)

In addition to "Diabetes Mellitus, Type 2/diet therapy", what other MeSH term is considered a major point of the article - indicated by the asterisk (*)?


This has been a brief introduction to MeSH terms and using them to search PubMed.

For more information, view the NLM video "Branching Out: The MeSH Vocabulary" and other resources on the PubMed online training materialspage. See also the UA Libraries' Searching PubMed tutorial.

Happy Searching!