One way to do a search using MeSH is to mine the terms out of some of the good results of your first keyword search – you can view them by clicking the MESH dropdown beneath the citation You can assemble relevant MeSH headings into a completely new search and edit the search after it is assembled if you want to remove subheadings, etc.
You can also assemble a MeSH search by looking up the terms from scratch. To do this, we return to the main PubMed screen and then select the MeSH database from the right-hand column.
The MeSH database functions like a thesaurus – you enter a term it tries to find the standard heading that is used in the index. In this way, MeSH tries to make sure that articles that might use different terms, but are “about” the same thing end up indexed with the same terminology. It will often give you several possible MeSH headings to choose from.
Once you have searched a term, you will get a list of possible MeSH index terms. You can select one by checking the box and then selecting “Send to Search Box” in the “Send to” dropdown menu OR you can click on the term to see more options. Note each term has a definition that shows you how the term is used in the index.
When you click on a term, it will give you a list of subheadings you might wish to use as well as showing the entry terms that are associated with this heading. It will also show you where your term appears in an index tree so you can see what terms would be consider broader or narrower. PubMed will automatically search for narrower terms when you do a search with MeSH. You can also tell it to search the topic only as a “major heading", or the primary content of the article. Once you have selected the term and options you wish to use, you click "Add to search builder", leaving the AND choice - this will make sure your final search strategy looks for all your terms in the same citation, rather than OR, which would just look for any of your terms.
After you have added the term, a PubMed search box will appear. It will remain in place, ready to continue compiling the search as you locate your next term.
When you locate your next term, you add it to the search box in the same manner, using the “Add to search builder” button
Once both terms are in place, you can edit the search if you need to and then click “Search PubMed” to run the search in the PubMed database.
Running the search using MeSH headings should give you a more focused, narrower set of search results.