The trilingual and structured vocabulary DeCS - Health Sciences Descriptors - was created by BIREME to serve as a unique language in indexing articles from scientific journals, books, congress proceedings, technical reports, and other types of materials, as well as for searching and retrieving subjects from scientific literature from information sources available on the Virtual Health Library (VHL) such as LILACS, MEDLINE, and others.
DeCS is a dynamic vocabulary totaling 31,580 descriptors, of which 26,936 come from MeSH, and 4,644 are exclusively DeCS. There is an addition of 1,994 hierarchic codes from DeCS categories in 1,507 MeSH descriptors. The following are the DeCS categories and their total number of descriptors: Health Surveillance (828); Homeopathy (1,945), Public Health (3,492); and Science and Health (219). The sum is greater than the total number of descriptors, since a descriptor may occur more than once in the hierarchy. By being dynamic, it records a permanent process of change including the development of new areas of terminology.