In the Nursing field, most often you will be searching the official Cumulative Index to Nursing and Allied Health Literature (CINAHL) subject headings. You should slowly become familiar with these subject terms when using CINAHL Plus With Full Text. Most often more specific medical terminologies will be used.
Causes [of disease] USE Etiology
While not official subject headings, these keywords can be very fruitful for your research. Try to also think of other terms such as these. Keyword searches look at all the information in the book or article record including title, author, abstract, table of contents, etc. It always helps to think of synonyms, as the way one person would describe something is not the same way another would.
Using the correct words to search will help you find relevant information. Different authors and search tools use different words to describe the same concepts, so it is useful to have a list of similar and related terms in your arsenal when you set out to search for relevant information. The process of creating these alternative terms is called brainstorming terms or concept mapping.
Brain AND Tumors