The Dictionary of Medical Terms of Clinical Anatomy Associates, Inc. is a work in progress. In the following pages we will present to you a listing of prefixes, root words, and suffixes, and the basic rules to combine these terms. We have tried to make the information as accurate as possible, but beware that this listing should be used as a guideline only. Should you want us to add terms to our dictionary, please feel free to e-mail us and let us know the term that you want to be added.

Our objective is to provide a basis for the study of Medical Terminology. In no case is this listing to be considered a substitute for a Medical Terminology Study Book. We strongly encourage you to acquire one of these books or take a Medical Terminology Course if you want to be proficient. To enter the Dictionary, please click here, or the titles at either end of this page.

Medical Words

Most medical terms are composed of building blocks: Prefixes, root words, and suffixes. Since these terms have their origin in different languages, we need to translate the meaning of the medical term to English. When translating the meaning of a medical word, most are read in the following order: suffix first, root word second, and prefix last. As such the term peri-cardi-o-centesis means: [centesis] needle aspiration [peri] around [cardi] heart.

In the Dictionary of Medical Terms prefixes, roots and suffixes are defined by "-'" as follows: prefix: prefix- / root: -root- / suffix: -suffix

Beware of the fact that many medical word components may be used as a root or as a prefix, but a few change their meaning according to their position. As an example "an" as a root word means "anus", but as a prefix, means "without".

Combining medical word components

These terms need to be combined following specific rules:

Prefixes:

Most of the times, when combining a prefix to a root word, you should just combine them by putting them together. In rare ocassions when the prefix ends in a vowel and the root starts in a vowel, the ending vowel of the prefix is eliminated. This does not happen all the times, so this rule is difficult to apply.

Root Words:

Root words are usually presented as a combining form, that is the root word followed by an "o" eg: "phleb" (root word meaning vein) and "phlebo" (combining form of the term vein)

When a root word need to be combined with another root word, and "o" is added in between the root terms. If applicable, the root words should be ordered from proximal to distal. eg: trache-o-bronch (itis)

Suffixes:

When combining a root word to a suffix, an "o" is added if the suffix begins with a consonant. eg: trache-o-tomy

When combining a root word to a suffix, an "o" is not added if the suffix begins with a vowel. eg: hepat-itis

When combining a root word to a suffix, if the root word ends in the same vowel that the suffix starts, eliminate the ending vowel from the root word. eg: card(i)-itis = carditis