What is PubMed?

PubMed is a free search database for scientific articles in medicine and health, among other fields. You can freely search and read abstracts, but full-text articles are not always available without a subscription or institutional access:

For access to articles NIH subscribes to, use this link:
https://pubmed.ncbi.nlm.nih.gov/?holding=inonihlib&otool=bibsys
Remember to be connected to the VPN client if you are off campus, otherwise you will not be able to open the articles we have access to.

Good to know!
The library provides instruction in literature searching in PubMed from 2nd year bachelor through to master's level. This will appear in your timetable.
Do you have questions about PubMed? Contact Anne Grete Gabrielsen by email: annegg@nih.no

Useful links:

https://pubmed.ncbi.nlm.nih.gov/help/

https://ntnu-no.libguides.com/PubMedguide

Follow the arrows for step-by-step guidance on searching in PubMed:

From research question to search strategy

Example of a simple research question:

How does physical activity affect the mental health of adolescents?

Identify your keywords:
physical activity, adolescent, mental health
Start with a simple test search by listing the keywords as you have identified them:

physical activity adolescent mental health

This retrieves articles containing all three terms and a test search means you

get fewer, but more relevant results
can quickly find one or two good articles
can see which terms researchers actually use (the same topic is often described using different words). If you only search for adolescent, for example, you may miss relevant articles that instead use youth or teenagers.

Create a search overview in a table

Once you have completed your test search and gathered additional relevant terms and synonyms, it is a good idea to structure your search more systematically. Consider creating a search overview — for example in a Word table — where you:

Add new words or phrases you discover
Remove terms that turn out to produce irrelevant results
Note which combinations gave the best results

This gives you a dynamic tool that you can update continuously as you find more relevant articles, which in turn may suggest new search terms.

Example of a search term table
3 topics	synonyms for each topic
physical activity	"physical activity" exercise workout "physical training" "physical fitness"
adolescent	adolescent teen* youth young girl* boy student* juvenile
mental health	"mental health" depression well-being "psychological health" anxiety

From table to a search string

Example of a table
3 topics	synonyms for each topic
physical activity	"physical activity" exercise workout "physical training" "physical fitness"
adolescent	adolescent teen* youth young girl* boy student* juvenile
mental health	"mental health" depression well-being "psychological health" anxiety

To build a search string you need to use Boolean operators (AND, OR, and sometimes NOT). Once you have your synonyms, combine them as follows:

Parentheses group synonyms together. In our example there are 3 topics, so you need 3 pairs of parentheses.
OR is used between synonyms. You want either one word or another, or a third, or all of them, etc.
AND is used between topics. You want all results to contain at least one word from each topic.

In our example, the search string will look like this:

("physical activity" OR exercise OR workout OR "physical training" OR "physical fitness") AND (adolescent OR teen* OR youth OR young OR girl* OR boy OR student* OR juvenile) AND ("mental health" OR depression OR well-being OR "psychological health" OR anxiety)

Read about quotation marks around phrases (two or more words that belong together) and the use of truncation (*) in the Toolbox section on Search smart – search techniques

Start your search in PubMed

Paste your search string into PubMed's search field and click Search.

Visual representation of a search in PubMed:

Screenshot from PubMed with the cite function open. An APA reference is displayed in a separate window.

When you run a search, you may often get a large number of results. This does not mean the search is poor — it may actually indicate that the topic is well researched.

Narrow down your search

Avoid using the filter options in the left margin when narrowing your search!

Using these filters can cause the most recent articles to not appear. It is, however, safe to use filters for language and/or publication year.

A smarter way to narrow your search is to add limiting terms directly to your search string. For example, if you only want randomised controlled trials (RCTs), you can extend the search string with a new set of parentheses:

("randomised controlled trial" OR RCT)

Your new search string will then look like this:

("physical activity" OR exercise OR workout OR "physical training" OR "physical fitness") AND (adolescent OR teen* OR youth OR young OR girl* OR boy OR student* OR juvenile) AND ("mental health" OR depression OR well-being OR "psychological health" OR anxiety) AND ("randomised controlled trial" OR RCT)

The number of results will decrease significantly, while relevance increases.

Temporary storage of PubMed references: Clipboard

You can save article references while working in PubMed:

Tick the articles you want to look at more closely.
Click Send to.
Click Clipboard.
The articles are now saved.

Visual representation:

Screenshot of PubMed showing how to select an article and click 'Send to' to save it to the Clipboard

After adding references to the Clipboard, you will see the count just below the search field. Click on it — in our example Clipboard (1) — and you will be taken to your saved references.

Visual representation:

Important to know:
This is temporary storage — as soon as you log out of the computer, references will be removed from the Clipboard. They remain available as long as you are logged in, and if you take a break (without logging out!), they will be stored for up to 8 hours.

Ordering articles from PubMed that NIH does not have access to

Anyone can search PubMed, but you will not always be able to read the full article.

In PubMed you will often only have access to the abstract of an article. NIH subscribes to many journals, so much is available — but not everything. If you find a relevant article you cannot open, you can order it via the Oria icon in PubMed.

How to do it:

When you are in an article's abstract, look for the Oria icon in the right margin.
Click on it.
Click Log in, then Feide.
Click Order document.

You will usually receive the article within 2–3 days.

It is typically delivered as a printed copy in an envelope with your name on it, placed in the shelves to the left of the self-service machine in the library. Occasionally you will receive it as a PDF by email — this depends on what the publisher permits (copyright).

Important to know:

Although it is free for you, each article costs the library at least NOK 120. So be mindful: do you really need this particular article?
Remember to be connected to the VPN client if you are off campus, otherwise you will not be able to open the articles we have access to.

Cite: Article references from PubMed in APA style

PubMed has a "cite" function that provides the PubMed reference in APA style.

This is a useful feature, especially for bachelor's students — it saves you from entering the full reference manually, which is particularly handy when an article has many authors.

However: The reference is not entirely correct, so you will need to make a few adjustments yourself:

Journal title: All major words should be capitalised.
Correct: Journal of Sports Medicine
Incorrect: Journal of sports medicine
Article title: Only the first word of the title and the first word after a colon (:) should be capitalised. (And proper nouns, of course).
Read more here: https://apastyle.apa.org/style-grammar-guidelines/capitalization
DOI: Always write the full address beginning with https://doi.org/.
Correct: https://doi.org/10.xxxx/xxxxx
Incorrect: DOI: 10.xxxx/xxxxx

MeSH Terms (controlled subject headings)

When you search in PubMed, you are searching a large, free database of medical articles. To explain MeSH terms, Medline must also be mentioned. Medline is the quality-assured part of PubMed. Here, articles are reviewed and assigned standardised subject headings known as MeSH terms. These subject headings help you find all articles on the same topic in PubMed, even when authors use different terminology.

Example: Strength training

Strength training can be described in many ways, e.g.: strength training, resistance training, strength exercise, or resistance exercise. If you only search for some of these terms, you may miss relevant articles.

Medline has determined that all articles on strength training should be assigned the MeSH term "resistance training" (regardless of which keywords the researchers used).

When you search for "resistance training"[MeSH] in PubMed, you will therefore retrieve most articles on strength training, regardless of which words the authors used.

Important to know

New articles may remain in PubMed for several weeks or months before being assigned MeSH terms by Medline — only then do MeSH terms and filters become visible. If you want to make sure you capture the most recent articles in your results, you should combine MeSH terms and free text (the authors' own words) in the same search.

About using [MeSH]

You do not need to add [MeSH] after a term to retrieve articles that have been assigned MeSH terms. PubMed will often match these anyway.

However, if your search is to be described in the methods section of an assignment, you should still indicate which MeSH terms you used. This allows readers and researchers to understand and replicate your search.

Search examples

Search with free text only:

("resistance training" OR "strength training" OR "strength exercise" OR "resistance exercise")
= 31,760 results (03.02.26)

Search with MeSH and free text:

("resistance training"[MeSH] OR "resistance training" OR "strength training" OR "strength exercise" OR "resistance exercise")
= 31,760 results (03.02.26)

Search with MeSH and less free text:

("resistance training"[MeSH] OR "strength training" OR "strength exercise" OR "resistance exercise")
= 25,878 results (03.02.26)

In this last example, you get fewer results because PubMed does not retrieve the most recent articles that have not yet been assigned MeSH terms.

Useful links

MeSH Database https://www.ncbi.nlm.nih.gov/mesh/

https://pubmed.ncbi.nlm.nih.gov/help/Links to an external site.

https://ntnu-no.libguides.com/PubMedguideLinks to an external site.