PubMed is a biomedical and life science database that includes over 21 million citations for articles, book chapters, and clinical trials.
Researchers can sometimes use the terms PubMed, MEDLINE, and PubMed Central interchangeably, but they are slightly different. When searching PubMed, you will receive results from both MEDLINE indexed journals and PubMed Central. You can read more details about the differences between the three here: https://www.nlm.nih.gov/bsd/difference.html
A new interface for PubMed launched in May 2020 and the legacy site was retired on October 31, 2020.
The default search in PubMed searches the entire record. It will also automatically convert your keywords to search additional terms (i.e. "automatic term mapping"). This can lead to a large number of results. In order to conduct more focused searches, use Boolean operators, truncation, and field tags:
|OR||At least one term must appear||liver OR cirrhosis|
|AND||Both terms must appear||addiction AND behavior|
|NOT||Exclude one term||lung NOT cancer|
|" "||Exact phrase search, looks for the exact phrase or word, tends to prevent automatic term mapping from occuring||"behavior" finds behavior, not behaviour|
|( )||Search inside the parentheses is executed first||(snake OR frog) AND behavior|
|*||Wildcard search, looks for the root word and alternate endings or beginnings||Enzym* will return enzyme, enzymes, enzymatic, and enzymology|
|n#||Proximity search, terms must be # number of words near each other, in any order||zika n2 virus|
|w#||Proximity search, terms must be # number of words near each other, in a order||"whole genome" w4 sequence|