Module 1: Foundations of MeSH in MEDLINE®

PubMed Searching & MeSH Terms

Advanced Search Builder

MeSH is structured and cross-referenced automatically to help you find the most relevant results when searching PubMed. You can dig deeper into how MeSH terms are mapped to a particular search result by going to the Advanced Search page and viewing the “Search Details”.

For example, here are the search details for our search on blood pressure:

Sreenshot of the PubMed Advanced Search Details for Blood Pressure

You can see this mapping wherever the [MeSH Terms] tag appears in your Search Details. This search tag directs PubMed to search in the MeSH section of the MEDLINE record. (Note: for a complete list of PubMed search tags, see the PubMed User Guide: Search field tags .)

Notice that these are the MeSH terms that were automatically mapped in the search:

  • Blood Pressure
  • Blood Pressure Determination
  • Arterial Pressure

Although the search details do not show the narrower terms, these MeSH terms also “exploded” to include narrower concepts, such as:

  • Pulmonary Wedge Pressure
  • Venous Pressure
  • Ankle Brachial
  • Blood Pressure Monitoring, Ambulatory
Sreenshot of the PubMed Advanced Search Details for Blood Pressure zoomed into the search details

Any citation indexed with any of these narrower terms will also be retrieved. If a term appears in multiple places in the MeSH hierarchy, all of its narrower terms will be included in a search.

You can use the Boolean operators AND, OR, and NOT to create specific searches in the query box.

Are There Limitations to Only Searching with MeSH?

While MeSH is an efficient system working in the background of MEDLINE/PubMed, it doesn’t cover everything that can be searched. Searching only within the MeSH fields can exclude some relevant results:

  • Terms that have not been added to the vocabulary yet – The MeSH vocabulary is a work in progress with updates made on an annual basis.
  • Citations outside of MEDLINE – PubMed also includes citations from PMC and Bookshelf.
  • Citations that have not been indexed yet – While citations are now automatically indexed, it is possible to experience a short lag between the time a citation appears in PubMed and when it is indexed with MeSH terms.