There are two basic types of search queries that most databases use: Keyword and Controlled Vocabulary.
Keyword searching allows you to enter a search term that you believe best describes the term as used in an information source. While this search strategy will retrieve what you've entered, you also need to search using synonyms and variations of the search term to make sure that you have retrieved all of the relevant records.
For example, if you are looking for information on "heart attack" using a textword search, you also need to search using the terms "heart attacks," "myocardial infarction," "myocardial infarctions" and so on.
Subject Searching (Controlled Vocabularies). Controlled vocabularies are standardized, hierarchical lists designated to represent the major subject concepts and conditions contained within a database. They can change from database to database. The hierarchical nature of the lists benefits search strategies by allowing broad concepts to be narrowed in a manner that stays consistent within that framework.
Before an item is added to a database or catalog, its subject matter is determined. Specific terms that apply to those subjects will be chosen from a pre-determined list, no matter what terminology the author used within the item. This way, there is a consistent method for retrieving the same information concepts even though different terminology has been used. The listing is standardized and somewhat predictable. For example, the term "heart attack" is always listed as "myocardial infarction" within a controlled vocabulary structure, such as MeSH (Medical Subject Headings), the vocabulary used by MEDLINE.
Adapted from Valpariaso University.
Enter a PMID
If you have a PubMed PMID (PubMed ID) or PMCID (PubMed Central ID) just enter that number in the PubMed search box.
Plan your research
Develop your research topic by composing an answerable question. Write your question in a complete sentence, being as specific as possible. For example, "What is the best diet for treating gout in patients with metabolic syndrome?".
Identify important keywords, terms, concepts and synonyms. Once you have clarified your search question, condense it down to the major concepts. Search for MeSH (Medical Subject Headings), or other keywords and phrases that describe the condition. If acronyms are used such as 'APT' also search the full-name in quotes: "adult treatment panel".
Search the right sources. The nature of your search question will determine what bibliographic database you will use. PubMed is an excellent first choice for most clinical research topics. It indexes over 5000 journals covering all of biomedicine, as well as the pre-clinical sciences. PubMed is freely available worldwide on the Internet. Check this link to learn about types of publications (primary, secondary, tertiary, peer-reviewed, etc.) to help identify which type you need to find.
Limit your results. You can often limit your search by age groups, gender, type of article, language, etc.
The Basics: Simple Searching & Viewing Results
For a basic keyword search, type the word or words you are looking for into the search box, and click Search. PubMed will suggest phrases that complete your entry or that are related to the words you're entering. The next page will show your search results.
Setting Filters (aka Limits)
Use the filters on the left sidebar to narrow down your results by specifying different categories such as language, type of article, age, gender, etc.
Changing the Display Settings
Click Display Settings at the top left hand of the page to change how much information you see for each citation, the number shown per page, and how they are sorted. Click Abstract from the pull-down menu, or click on the hyperlinked article title, to see the citation, abstract, and related records information.
Look for the icon or another "free full text" icon in the top right of the abstract page, and click the icon to access the full article text.
Saving, Printing, and Emailing Search Results
As you search PubMed you can temporarily store articles of interest on the Clipboard. To add an article to the Clipboard, check the box next to the article, and select Clipboard from the Send To link located to the upper-right corner above your search results. You will get a message stating that your article has been posted to the Clipboard.
After you have placed items in the Clipboard, a link to the Clipboard will appear at the upper-right of your screen. To view all the items in the Clipboard, click that link. Articles already posted to the clipboard are marked below their citation information with "Item in Clipboard" in both the Summary and Abstract displays.
From here, you can decide what you would like to do with your citations. Using the Send To menu:
To print your citations, select Print from your Internet's browser window.
To remove an item from the Clipboard, click the Remove from Clipboard link below the citation.
Adapted from UNC Health Sciences Library.