The Medical Subject Headings (MeSH) of the thesaurus of the database MEDLINE can be retrieved via the portal PubMed of the National Library of Medicine, USA, and can be used for searching the database.

The MeSH thesaurus contains over 26,000 controlled items, mostly health care terms. The hierarchical arrangement of the items according to ISO standard 2788 and ISO 5964 in  broader terms and narrow terms facilitates a precise search of the database MEDLINE.