Subject Guides: How to use PubMed: MeSH Search

Introduction to MeSH terms

MeSH is a pool of medical terminology with very specific definitions for each word.

They are used to tag articles with the relevant content in databases like PubMed, Cochrance. Using the Medical Subject Headings. (MeSH) is efficient because they search for matching content rather than text.

Where can you find MeSH tags?

For any particular article, the related MeSH terms can be found at the bottom of the Article record page.

Searching with MeSH terms

Searching with MeSH terms retrieves articles with content specific to the MeSH term searched.

E.g. searching with the MeSH term "Hypertension" will bring you specific articles that are relevant to the condition related to "High Blood Pressure". If you have searched using "High Blood Pressure" as the keyword, you will get more results but not all articles will be relevant, especially when you are searching for clinical information on how to deal with this condition. Searching with MeSH terms, will also mean that you save time to search using varied search terms pertaining to the condition or second-guessing how the condition will be reflected in the paper.

Choosing your specificity.

MeSH terms have a "hierarchy". The more specific the term is, the lower it is on the MeSH term tree, the less articles there are with such specific content. Conversely, umbrella terms such as "Diabetes mellitus", which defines disorders characterised by high blood sugar and glucose intolerance will retrieve more articles less specific to any one disorder. This hierarchy shows the relationships between terms and get lead you in finding terms that you might not be aware of

Below is an example of a MeSH term tree

To search with MeSH terms, one needs to retrieve the MeSH terms describing exactly what you're interested in from the MeSH database and add it into a Search Builder.. Please note that you can only retrieve MeSH terms in your results and not related articles. Select your desired MeSH terms and add them into the Search Builder to search in PubMed.

A Search Builder helps you to narrow or expand your search by combining multiple MeSH terms with Boolean operators (AND, OR and NOT) and retrieve results with the relevant content.

As always, you must also be “flexible” to not use MeSH if you yield too little results.

Step 1: At the MeSH database page, key your subject matter into the search bar and select the most relevant MesH term from the database.

Example:

Step 2: After clicking the search result, a page detailing the definition of the MeSH term will load.
Select the MeSH subheadings that you're interested in, then click "Add to search builder" at the top right corner of the page.

Step 3: After clicking the subheadings you want, you can narrow your search or widen your search. Only the related subheadings to the MeSH terms will appear.

To expand your search results (include articles with any of the subheaders for the major heading that you have chosen), check multiple subheadings and clicked "Add to search builder". PubMed will process it with the "OR" Boolean operator
To narrow your search results (only include articles with all the subheadings that you have chosen), check one subheading then add it to the search builder, and repeat with another subheading. PubMed ;will process it with the "AND" Boolean operator.

Expanded search build	Narrowed search build

When you have constructed your desired search, click "Search PubMed" below the Search Builder.

To reuse your search terms, copy the current Search Details (found at the bottom of the right most column of the page, as shown below). and paste your copied Search Details into the Search Builder before clicking "Add to Search Builder" and clicking "Search Pubmed". This will allow you to include your search results. If you want to expand your search, make sure the terms are connected via the "OR" Boolean operator.