MeSH stands for Medical Subject Headings and is the controlled vocabulary used in PubMed searches. Using the MeSH database will ensure that you search collects all of the citations about your topic. In addition, the MeSH database will help you limit your search to the specific areas of your research topic.
Searching the MeSH Database
Divide your topic into components before searching. For example, in the question "does physical therapy reduce pain in fibromyalgia patients," the topic is made up of three components: physical therapy, pain, and fibromyalgia.
Search on the first component—fibromyalgia. Automatic term mapping is used here as well to guide to the best result. Click on the result that matches your term most closely.
Subheadings will do a lot of the work for you. After clicking on fibromyalgia, you are presented with a list of subheadings. Two subheadings could fit our topic—rehabilitation and therapy. Put checks in those check boxes.
Major Topic Headings and Exploding Terms
The major topic headings check box will limit your results to citations which are specifically on your topic. "Do not explode this term" tells the database not to use other related terms in the MeSH tree hierarchy.
Sending Results to the Search Box
The search box will let you build your search inside the MeSH database before sending your search to PubMed. After selecting your subheading(s), click on the "Send to" drop-down menu. Select "Send to Search Box with OR" which means you don't care if the citations are about rehabilitation or therapy since either fits the search.
Adding a Second Topic
Now search in the search box for your second concept--pain. Select the concept and send it to the search box with AND. If you have additional concepts, you can keep adding concepts until your research question is fully developed.
Sending Your Search to PubMed
After you have finished adding concepts, click the "PubMed Search" button. Your search will now be executed in PubMed, and you can use PubMed as you usually do. Limits can be added now.