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Searching CINAHL

Searching with Subject Headings

Subject headings are words or short phrases that are added to the records of every reference in the database. Subject headings use a ‘controlled language’, meaning there is only one word or phrase used to describe a specific concept. In theory, this means that every reference discussing melanoma will have the ‘melanoma’ subject heading. Searching using subject headings will retrieve references on a topic regardless of the wording used by individual authors.

  • Search for each term one at a time. CINAHL is unable to interpret multiple subject headings all at once.

Example search topic: Palliative care of terminally ill patients with melanoma.


For this example, we will search for subject headings for melanoma and then for palliative care, beginning with the melanoma search term.

  1. Enter your first search term and click the Search button.
    • Suggest Subject Terms is ticked by default. Leave this option selected.
    CINAHL - Search example Melanoma
  2. You will see a list of possible subject headings. If you are unsure of the meaning or scope of a heading, click on the scope note.
  3. Find the heading that best matches the meaning of your search term, and click on it to see the Tree structure (which shows the subject headings in context.)

    Example search topic: Palliative care of terminally ill patients with melanoma.


    For our search example, Melanoma is the best match.

    • If more than one heading matches, choose one, and come back to include the other heading when you have completed the steps below.
    • Not every search term will have an appropriate subject heading. If you can’t find one that matches, just do a keyword search.

Tree structure

Clicking on a heading will take you to the tree structure, which shows where the heading sits in the context of other headings. You can choose more general, more specific, or a combination of headings that look relevant to your search term

Explode and Major Concept

For your chosen heading(s), you have the option to explode the heading(s), make the heading(s) a major concept, or both.

  • Explode includes your selected subject heading and more specific headings. This will increase the number of results.
  • Major Concept retrieves references that have this subject heading as their main topic. This will find fewer results, but with higher relevance.
  • Both includes your selected subject heading as well as more specific headings, and only retrieves references that have any of these headings as their main topic. This broadens the scope of the search, while also increasing the specificity of the results.

Tick the relevant boxes as appropriate:

Consider subheadings for very specific aspects

The default option is to Include all subheadings. This will ensure you see all of the results for your chosen subject heading, and is the option we recommend for the majority of searches.
You have the option to narrow your results further by selecting specific subheadings from the list. However, this can be very restrictive and may cause you to miss relevant references. Use with caution.


Once you have made your selections, click on the Search Database button in the top right corner and your first set of results will appear:

The first set of results should look something like this: