PubMed is the National Library of Medicine's (NLM) freely accessible interface to the MEDLINE bibliographic database, covering the fields of medicine, nursing, dentistry, veterinary medicine, biomedical engineering, the health care system, and the basic biomedical sciences.
MEDLINE contains bibliographic citations and author abstracts from more than 5,000 biomedical journals published in the United States and 80 other countries. The database contains over 15 million citations dating back to the mid-1950's. Coverage is worldwide, but most records are from English-language sources or have English abstracts. Journal articles are indexed for MEDLINE using NLM's subject heading system, MeSH (Medical Subject Headings).