Subject Headings are specifically defined terms used to identify topics throughout a database. Not all databases use subject headings, and some that use them don't allow you to search them specifically.
Many of the main health science databases have subject headings, and they can be searched by going to the link at the very top of the page:
Click MeSH (or the other subject heading links) to search for a topic.
Enter a term in the search box. Only search for one term at a time. The options under the search box go from most specific to least, moving left to right.
MeSH uses medical terminology: Myocardial Infarction is the medical term for heart attack.
Clicking on the subject heading will bring up a hierarchical list, the "tree view", with broader, narrower, and related terms.
Checking the box to the left will bring up subheadings designed to focus on an aspect of the topic: Therapy, Etiology, Diagnosis, etc. The options vary according to the term. (These are optional.)
At the bottom of the Subheadings list is a Note that explains aspects, history, and use of the term. You may see clues to alternate terms and historical notes for searching older articles.
The other two check boxes are Explode and Major Concept.
Everything you check is reflected in the Search box on the far right. (You may have to scroll over on a small screen.)
The Subject Heading is Myocardial Infarction with a subheading of diet therapy, including all narrower terms and as a major concept of the article. I can now either do the search or look up another term. To get back to the term lookup, click Back to Term List at the top of the "tree" view, and/or scroll down to the bottom of the term list for "Browse additional terms".
When you select another term, you get the option to Combine Selections with AND or OR. AND requires that both terms be in the results. OR is used for alternative terms (African Americans OR Hispanic Americans).
Note: there are no narrower terms for African Americans, so even though the Explode box is there, it's grayed out and not checkable.
Clicking the Search Database button will do the search. Once the search is done, you can go to the Advanced Search and select options like Age Groups or Publication Types. See the Advanced Search box in the Basic Health Sciences guide for more on the Advanced Search options.
When searching more than one database, using the subject headings from one database will usually block out results from the other databases, because subject headings are database specific.
Use additional terms within your search. Use OR between words to tell the database that the terms are alternatives to each other:
teenager OR adolescent
cocaine OR heroin OR marijuana OR illegal drugs
Can't think of additional terms? Try Google's thesaurus search: