Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

MEDLINE Indexing Online Training Course

Category G - Phenomena and Processes

Indexing Principles

Terms in Category G are almost always coordinated with a MeSH heading (anatomical structure, organism, disease, or drug) /subheading combination. Earlier in this course, indexers were instructed to always "scroll down" the tree to verify that they selected the most specific term available. Indexers should also scroll up the tree. This is particularly important when indexing biological processes or phenomena because the name of the Category G subtree would determine the selection of the correct subheading for the anatomical structure, organism, disease, or drug. For example OXYGEN CONSUMPTION is treed under METABOLIC PHENOMENA, so the correct subheading for the organ, organism or disease where oxygen consumption is taking place would be /metabolism.

Neutrophil infiltration into the liver

Neutrophil infiltration is treed under IMMUNE SYSTEM PROCESSES, so the subheading on LIVER would be /immunol.

Last Reviewed: March 10, 2015