PubMed is the free public interface to the database MEDLINE, created by the National Library of Medicine (NLM). PubMed comprises more than 32 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links directly to full-text content.
The search screen below is the starting point for all PubMed database searches. Once you have decided on the keywords you want to search, type one of your keywords into the search bar. If you would like to use MeSH terms, please click the tab to the left for instructions.
Searching by Concept
It is often a good idea to break your research into concepts, then search for each concept separately, using all of the appropriate terms possible. For example, let's say you are researching the connection between high blood pressure and varicose veins. You would do two separate searches, one on each concept, then combine them. PubMed saves your search results for eight hours, or until you log off. You could search on:
- "high blood pressure" OR hypertension and then, in another search:
- "varicose veins" OR "spider veins" OR varicoses or varicosities
Now you need to find articles that pertain to both hypertension and varicose veins. We'll do this by combining the searches. To find your searches, click the Advanced link beneath the search box. In Advanced Search, you will see your search history.
In this case, we want articles that pertain to hypertension AND varicose veins. Click the three dots in front of one of the search strings, and then "Add Query". You will see that doing so populates the "Query Box" in the search builder above.
Now go to your second search string, click the three dots and choose "Add with AND". This adds our second concept to the Query Box above. This is telling PubMed that we want articles about both hypertension AND varicose veins.
Limiting Your Results
The search above gives us over 1500 results. We can refine these results by using the filters to the left. For example, we can limit by date of publication. Choosing "Additional Filters" allows you to limit by language, species, age, type of publication and many more. Limiting results to the past 10 years along reduces results to less than 500.
Another way to refine results is to limit citations returned to those in which the keywords show up in the title or abstract. To do this, construct your search string as above and search on it in PubMed. Go into Advanced (right under the Search box) and change the dropdown box for "All Fields" to TItle/Abstract, then hit search. Do this for each search string, and then combine results as shown above.
At this point, you probably want to add your citations to RefWorks or another citation management system. For help adding your citations to RefWorks, click the Saving PubMed Results to RefWorks tab to the left.
MeSH stands for Medical Subject Headings and is the vocabulary that helps to organize the citations found within the MEDLINE database. MeSH terms can be used as a retrieval tool. The NLM has tagged each article in PubMed with a handful of appropriate MeSH terms. When you search for a MeSH term, all articles that were tagged with that MeSH term are retrieved.
Suppose you wanted articles about how different cultures view a particular medical procedure. If you search on the word Culture in PubMed without using MeSH, you get articles about tissue culture, Petri dish cultures, etc. MeSH requires that you choose one (or more) subject heading related to culture, including ethnography, organizational culture, tissue culture techniques and more.
Let's say you want to research injuries incurred by young pitchers. These articles could be found by using the keywords "repetitive stress," "Little League Shoulder," "growth plate," "stress fracture" and many others. Instead of searching on each of those terms, you can use a single MeSH term (in this case, "repetitive stress") that captures them all.
It is not always necessary to search for MeSH terms, as PubMed automatically searches for MeSH terms when possible. If you search for a keyword for which a MeSH term exists, PubMed automatically searches for that MeSH term. Also, it can take up to six months for MeSH terms to be applied. If you search using MeSH terms exclusively, you will miss the most recent articles.
To begin to search with the MeSH database, click on the PubMed logo (from any page)
This brings you back to the main PubMed search screen. Look for the link for the MeSH Database (under "Explore")
This brings you to the MeSH database, where you can locate your MeSH terms. To start, type a keyword into the search box.
MeSH terms that pertain to that search term will appear.
Choose the most appropriate one(s) and they will auto-populate in the PubMed Search Builder to the right.
You can click "Search PubMed" and you will be brought back to PubMed, and the results shown will be those citations returned by this MeSH seach. Another way to search on MeSH terms is to COPY that phrase from the PubMed Search Builder. (shown above) then go back into PubMed and PASTE it into the PubMed search box.
To get back to PubMed, change the drop-down box from "MeSH" to"PubMed."