This is a list of roots, suffixes, and prefixes used in medical terminology, their meanings, and their etymologies. Most of them are combining forms in New Latin and hence international scientific vocabulary. There are a few general rules about how they combine. First, prefixes and suffixes, most of which are derived from ancient Greek or classical Latin, have a droppable -o-. As a general rule, this -o- almost always acts as a joint-stem to connect two consonantal roots (e.g. arthr- + -o- + -logy = arthrology), but generally, the -o- is dropped when connecting to a vowel-stem (e.g. arthr- + -itis = arthritis, instead of arthr-o-itis). Second, medical roots generally go together according to language, i.e., Greek prefixes occur with Greek suffixes and Latin prefixes with Latin suffixes. Al