MeSH, the Medical Subject Headings, is the vocabulary the National Library of Medicine (NLM) uses to describe the biomedical literature. If you search PubMed for the research behind a clinical question, or for residency research work, knowing MeSH makes your searches more complete.
What MeSH is
- NLM describes MeSH as "a controlled and hierarchically-organized vocabulary produced by the National Library of Medicine," used for indexing, cataloging and searching biomedical and health information.
- It includes the subject headings used in MEDLINE/PubMed and the NLM Catalog.
- Descriptors and qualifiers are released annually, and PubMed citations are updated each year with new terminology.
Why it helps your searches
Authors describe the same idea in different words. PubMed maps your search terms to MeSH, the vocabulary NLM uses to describe articles, to add related terms to your search, and this happens automatically. Searching directly with a MeSH term can make a search more precise.
How to use it
- Open the MeSH Browser from NLM and search for your concept, such as a disease or a drug class.
- Look at where the term sits in the hierarchy; narrower terms are included under a broader one.
- Use the MeSH Database to build a PubMed search, then add other words for the exact question.
- Read the abstract and methods, not only the title, before you rely on a paper.
How it links to the USMLE
Step 2 CK and Step 3 include interpretation of the medical literature (see the USMLE Step 2 CK guide and USMLE Step 3 guide); see biostatistics and epidemiology. For applicants, the same searching skill helps when you research programs and prepare for interviews.