MeSH stands for Medical Subject Headings and is the vocabulary that helps to organize the citations found within the MEDLINE database. MeSH can be used within MEDLINE to assist users in finding the appropriate terms for their search.
MeSH reviewers read articles before they go into MEDLINE and assign appropriate subject headings to the article. These subject headingsare from a pre-set list (or vocabulary). MeSH applies one term to a collection of concepts - even if that exact term is not used in the article.
Suppose you wanted articles about how different cultures view a particular medical procedure. If you search on the word Culture in PubMed without using MeSH, you get articles about tissue culture, Petri dish cultures, etc. MeSH requires that you choose one (or more) subject heading related to culture, including ethnography, organizational culture, tissue culture techniques and more.
Let's say you want to research injuries incurred by young pitchers. These articles could be found by using the keywords "repetitive stress," "Little League Shoulder," "growth plate," "stress fracture" and many others. Instead of searching on each of those terms, you can use a single MeSH term (in this case, "repetitive stress") that captures them all.
To begin to search with the MeSH database, select MeSH from the drop down menu to the left of the search box. This menu is present on every screen throughout the PubMed database. You may always select MeSH from this menu.
The MeSH database always provides a definition of the term. Users should make sure that the MeSH definition of the term aligns with the item you are searching for. This is the entry in the MeSH database for the term Portal Hypertension.
Once you find the correct term in MeSH, you can select that term by using the search box found at the right side of the page. Once you have chosen the term you wish to search, click add to search builder to place the term in the Search Builder box. Click the Search PubMed button when you are ready to search.