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PubMed

Keyword Searching in PubMed

When starting a search in PubMed you might want to begin with keywords to find anything that mentions the words you list. From there you might want to think about narrowing by adding more keywords, utilizing MeSH, and selecting filters (not sure what some of these words mean? we explain them on these pages). Use the information on this page and Narrowing a Search to learn more.

Keyword and Subject Searching

Keywords Subjects
Natural language words that describe your topic Pre-defined "controlled vocabulary" that describe what an item is about 
More flexible search - looks for anywhere the words appear in the record Less flexible search - only the subject fields will be searched
Broader search, but may yield irrelevant results Targeted search; results are usually more relevant to the topic, but may miss some variations

Keyword searching is how we normally start a search. Pull out important words or phrases from your topic. 

Subject Terms and/or Headings are pre-defined terms that are used to describe the content of an item. These terms are a controlled vocabulary and function similarly to hashtags on social media.

Icon of a check markQuick Tip: In PubMed Subject Headings are referred to as MeSH which stands for Medical Subject Headings.

We are indebted to the MIT What are subject headings and keywords? box and Sarah Lawrence Finding Resources Guide for some concepts displayed here.

You can use the MeSH box on our Narrowing a Search page on this guide to learn more about MeSH and how to best use it.

MeSH terms can be found at the bottom of the article record within PubMed or by searching the MeSH database.

Image showing that to access MeSH terms in an arricle record click on the "Publication Types, MeSH Terms" towards the bottom of the page.

You can then click on the dropdown arrow to be given options to search the term in PubMed, Search the term in MeSH (which basically acts like a thesaurus to find the subjects and subheadings PubMed utilizes for the keyword), or to add it to your search.

Image of the MeSH term dropdown options to "Search in PubMed," "Search in MeSH,' or "Add to Search."

Create a Search Using Commands

1. Isolate keywords from your topic.

Image that lists the question "How does cultural competence impact the health care system in the United States? With cultural competence, health care, and United States highlighted to show how to pull them out in a search.

2. Narrow your search results to include all of your keywords using AND.

"United States" AND cultural competence AND health care

Venn diagram that has "United States" AND "Cultural Competence" AND "Health Care" to try and display how when using Boolean Operators the three intersect.

3. Expand your search using OR to find like terms.

"United States" AND "cultural competence" AND ("health care" OR healthcare)

Combining search terms with AND:

  • Narrows your search, reducing the number of results.
  • Makes the search focus more specifically on your topic.

Vin diagram that indicates how AND intersects (example written out in text in this box).

For Example

A search for "United States" yields 314,000 results results

A search for cultural competence yields 1,700 results

A search for cultural competence AND "United States" yields 429 results

Combining search terms with OR:

  • Expands your search and increases number of results.

Vin diagram that indicates how OR intersects (example written out in text in this box).

For Example

A search for "health care" yields 263,000 results

A search for healthcare yields 170,000 results

A search for "health care" OR healthcare yields 317,000 results

Combining search terms with NOT:

  • Narrows your search, decreasing your search results.
  • Tells the search to exclude certain terms.

Diagram that indicates how not works, when you use it for by saying NOT family you find caregiver without the word family (example written out in text in this box).

For Example

A search for caregiver yields 13,300 results

A search for caregiver NOT family yields 6,700 results

Use Quotation Marks to:

  • Narrow your search.
  • Combine search terms that are more than single worlds.

This shows the search engine that you want the terms to be found together. The search will look for exactly what you place in the quotation marks, so be sure there are no mistakes.

Vin diagram that indicates how quotation marks keep phrases together (example written out in text in this box).

For Example

A search for United States yields over 500,000 results

A search for "United States" yields about 300,000 results

Use Truncation to:

  • Expand your search.
  • Give your search tool flexibility to find alternate endings for your search term.

Diagram that indicates how truncation works (example written out in text in this box).

Search engines match your exact terms to results; they will not automatically find an alternate version of it. Truncation tells the search to match the root of your term and gives it freedom to find whatever endings it can.

For Example

A search for cultural yields 36,000 results

A search for cultur* yields over 95,000 results

These commands are called Boolean Operators.

Boolean

1. denoting a system of algebraic notation used to represent logical propositions, especially in computing and electronics.

What does that mean for you?

If you are having a hard time finding what you need, use the Boolean Operators outlined here to more efficiently search databases.

No matter where you are searching - the catalog, Google Scholar, a database you will want to use Boolearn Operators to refine your search to your specifications.

We are indebted to the Butler University Library's And/Or/Not box and to the Sarah Lawrence Create a Search Using Commands box for some of the content displayed here.

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