Recently, we are observing an exponential growth in the production of scientific literature. While this has benefited us gaining new knowledge in education and healthcare, it also makes it difficult for us to locate the best information on a topic. When conducting literature searches for finding scientific studies, using National Library of Medicine’s (NLM) Medical Subject Headings (MeSH) thesaurus is crucial. Searching with MeSH could add value to your literature searching skills and increase precision to the search results.
What is MeSH?
MeSH are the official vocabulary that describe the subject content of an article in Medline. It branches out from broader to narrower terms that are arranged in a hierarchical order. There could be typically 5-12 vocabularies assigned to articles that are indexed in PubMed (Medline).
Where can you find MeSH?
- On the Entrez MeSH database; it is also available at the bottom of PubMed homepage that allows to build searches.
- Ovid Medline database, Clinical Trials.gov, and Cochrane library
- Directly from NLM’s standalone MeSH Browser to find the vocabularies.
What’s new about MeSH?
NLM ensures accuracy of MeSH with annual revisions and updates. In 2025, there are interesting expansions, additions, and deletions that might help you to improve the research. Below are some examples

MeSH Tutorials
Have a suggestion to improve the subject headings and/or vocabularies? Write to NLM help desk.
Want to discuss and learn more? Connect with one of the research librarians