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PubMed @ UMSL

Step-by-step guide to PubMed's basic and advanced features, with downloadable handouts.

Anatomy of a MeSH Term in the Database

Full database entry of the MeSH term Eye Enucleation, showing the 4 sections outlined in the text.


In addition to the MeSH term, scope notes, and introductory year, you will see the following sections for most Database entries:

 1  Search builder options

  • Subheadings that have been used with this heading. Subheadings are qualifiers that provide context for a term and are useful for drilling down further into the topic. To learn when to use particular subheadings, click on the Subheadings link above the checklist.
    • When you select a subhead and add it to the Search Builder, it will appear after a forward slash (e.g., "Eye/physiology"[Mesh], where "Eye" is the MeSH heading and "physiology" is the subheading).
  • Restrict to MeSH Major Topic. Checking this box will force PubMed to only search for articles in which the term and any selected subheadings are indexed as a major topic.
    • When you choose this option and add to the Search Builder, you will see [Majr] after the heading (e.g., "Eye/physiology"[Majr]).
  • Do not include MeSH terms found below this term in the MeSH hierarchy. By default, PubMed automatically "explodes" the term when it searches, meaning it looks for the term and all terms below it in the hierarchy (i.e., more specific terms). You can see the hierarchy farther down on the database entry page. Clicking this exclusion option will prevent automatic explosion.
    • When you select this option and add to the Search Builder, you will see NoExp (i.e., no explosion) in brackets (e.g., "Eye/physiology"[Mesh:NoExp] or "Eye/physiology"[Majr:NoExp]).

 2  Entry terms and similar terms (if present)

  • Entry terms are synonyms, alternate forms, and other closely related terms  that are generally used interchangeably with the preferred term for the purposes of indexing and retrieval.
  • Similar terms are synonyms and related terms that are not interchangeable with the preferred term but are suggested for potential exploration. You'll find these listed under "See Also" (see the terms provided for MeSH term Eye, below).

Entry terms and similar terms for the MeSH heading Eye.

 3  Position in the MeSH hierarchy

  • Each "tree" shows where your term falls in the topical hierarchy—from most general to most specific.
  • Broad terms (such as Eye, below) will have multiple branches, categories, and subcategories. (Plus signs indicate the presence of even more specific terms.)
  • Some terms will appear in more than one branch (e.g., Eyelids and Conjunctiva in the image below)
  • Remember that the goal is to find the most specific term to search. So if the main focus of your research is damage to the cornea, you would do better to search Cornea than Eye. This visual hierarchy can be a powerful tool!

MeSH hierarchy for Eye, showing its position in two branches: Body Regions and Sense Organs. The Body Regions branch shows Eye has three more specific terms--Eyebrows, Eyelids, and Eyelashes--whereas in the Sense Organs branch Eye has numerous more specific terms, including Anterior Eye Segment and all of its subordinate terms, such as Conjunctive, Cornea, and Iris.

 4  PubMed Search Builder

  • Using this tool, you can run searches directly from the MeSH Database. (See the following box for instructions.)

Search Builder Basics

Using the Search Builder isn't really difficult, but using it effectively can be a bit of a challenge. Here are the basics:

  1. Use the MeSH Database's scope notes and topical hierarchy to find the most specific term you can.
  2. Select any subheadings you feel are appropriate to your search.
  3. Decide whether you want to restrict your search to MeSH Major Topic or forego automatic explosion; if yes, check one or both boxes.
  4. Click the Add to search builder button.
  5. Review the search details and make any necessary adjustments. Remember to clear it if you want to change your selections for a particular MeSH heading.
  6. If necessary, add another term with subheadings and restrictions until your topic is covered. Combine the searches using AND (usually).
  7. Click Search PubMed.

Below is an example of a search built around complications arising from eye removal. Note that I selected the MeSH term Eye Enucleation, with a subheading of adverse effects, and that I restricted my search to articles in which this is a major topic. (Because Eye Enucleation is the most specific term in its hierarchy, I didn't select the second restriction as it would have had no effect.)

You can see each of my selections reflected in the search details: "Eye Enucleation/adverse effects"[Majr]. At the time this search was run, it produced 72 highly relevant results.

Example of a search built in the MeSH Database, showing selection of one subheading and restriction to MeSH Major Topic, as well as the hierarchy at the bottom of the page and the search builder in the top right corner that includes the Search Details.

Search Builder Advanced Tips

Most concepts cannot be adequately described with a single MeSH term, so an effective search will require some advanced techniques. Here are a few examples of common search strategies. The terms in bold italics are ones you will search for in the MeSH Database. A forward slash (/) indicates that a subhead follows.  NOTE  It doesn't matter in what order concepts are ANDed together.


To find articles that discuss the use of a particular medication to treat a particular disease

Disease/drug therapy AND Drug/therapeutic use

 EXAMPLE  Multiple Sclerosis, Relapsing-Remitting/drug therapy AND Alemtuzumab/therapeutic use


To find articles that examine the use of a particular type of therapy in the rehabilitation of a particular condition

Condition/rehabilitation AND Type of Rehabilitation

 EXAMPLE  Hand injuries/rehabilitation AND Exercise Therapy


To find articles about a nurse's role in treating a particular condition

Type of Nurse AND Condition/nursing

 EXAMPLE  Orthopedic Nursing AND Hip Fractures/nursing