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MEDLINE Indexing Online Training Course

Category G - Phenomena and Processes

Indexing Principles

Category G contains an extensive array of terms for biological, chemical, physical processes and phenomena. It also includes terms for mathematical concepts.

Biological phenomena include a wide variety of terms covering

  • physiologic
  • immunologic
  • genetic
  • biochemical and pharmacologic processes or phenomena

The MeSH terms from this category tend to be very specific. The indexer must always check the tree to make sure that the most specific term is selected.

Terms in category G are frequently coordinated with one of the following,

  • an anatomical term
  • an organism term
  • a disease term
  • a drug term

with the subheadings /physiol / physiopathol (diseases only), /metab, /genet or /immunol.

Body temperature regulation in obesity
OBESITY / *physiopathol

Glycolysis in the liver.
LIVER /*metab

Category G terms tend to be IM. However, some terms tend to be NIM coordinates for IM terms in other categories. For example, DIGESTION would likely be IM but OXIDATION-REDUCTION would be NIM, except in very general articles on oxidation-reduction per se. Check the MeSH annotations of each term for guidance.

Last Reviewed: March 10, 2015