Medical Terminology - Chapter 1

GENERAL RULE:  Slash all words according to how the elements are presented in this class.  Appendix A, Page 483, will be used as this class’s reference point.

The purpose of this portion of the course is to provide a vocabulary which will assist you in communicating properly between doctors and patients, and to help in understanding the scientific literature.

Medical Term - A medical term is a word or phrase made up of elements to express a specific idea.

Element:  A word part used to form a medical term.  All elements in a medical term are essential to its meaning.  Each element is a medical term has its own meaning. The book describes these as Word Roots.  Word Roots are presented in Bold/Magenta in the book.


            Element   Element Element   =   Medical Term

              Nephr        aden         oma       =    nephradenoma


There are 3 types of elements:

ROOT (ELEMENT) - The main element within a Medical Term.  Often there is more than one root element within the medical term.  The root element is always the subject or main topic of the medical term.  Roots frequently refer to a body part.

PREFIX (ELEMENT) - An element at the beginning of a medical term which changes in some manner the meaning of the medical term or makes it more specific.  Can refer to Location, Time, Number or Status


Prefix     +     Medical Term = Medical term w/ Prefix

Hemi       +     gastrectomy  =      hemigastrectomy

SUFFIX (ELEMENT) - an element at the end of a medical term (after the root element) which frequently describes a condition of a body part or an action to a body part.  Can also refer to a Procedure, Condition, Disorder or Disease

 Additional Medical Terminology Components include:

 WORD TERMINAL - a word terminal is a suffix or word ending which denotes the part of speech of the medical term (noun, verb, adjective).

COMBINING VOWEL - a combining vowel (usually O or I and less frequently U) is used between two elements of a medical term to make the term easier to pronounce.  Occasionally the other vowels may be used.


Without combining vowel: hepatmalacia (hepat/malacia)

With combining vowel:      hepatomalacia (hepat/o/malcia)

Examples of word terminals:

 The following word terminals are used in your everyday vocabulary:  (See Page 483 for full list)

Adjective terminals (pertaining to)    Noun Terminals

-ic                                      -y

-al                                     -ia

-ical                                   -um

-ac                                     -is

WORD ROOT with Vowels = COMBINING FORM - a combining form is a root with an added combing vowel which the root usually carries when used in combination with another element.


 Root + combining Vowel + Element   =   Medical Term

Gastr             o                      enteric =    gastroenteric



To be certain that you are accurately interpreting a medical term, always refer to an authoritative medical dictionary. Failure to do this may result in the inaccurate in interpretation of medical terms.

Example:  cardiectomy (cardi=heart, ectomy=surgical removal of all or part of)

Therefore, one might reasonably (but inaccurately) assume that cardiectomy means surgical removal of all or part of the heart.  To quote one authoritative source, cardiectomy means "surgical removal of the upper end of the stomach.)

NOTE:  The meaning of this medical term was probably derived from the fact that the upper end of the stomach is the cardiac end or the end toward the heart.  In any case, it clearly emphasizes the importance of referring to an authoritative medical dictionary rather than accepting the literal interpretation of a medical term.

 To determine a Medical Term’s meaning by looking at the component pieces, you must first separate it into the individual Elements and Word Roots.  Some tips:


 Oto/rhin/o/laryng/ology – study of the ears, nose and throat


Rules for using Combining Vowels:

  1. A combining vowel is not used when the suffix begins with a vowel (A-E-I-O-U)

  2. A Combining Vowel is used when the suffix begins with a Consonant

  3. A Combining Vowel is Always used when 2 or more root elements are joined

  4. A Prefix does not require a combining vowel.  Do not place a combining vowel between a prefix and the word root

Page 5 gives examples of Suffixes:

Suffixes related to Pathology – path/ology – pertaining to disease or illness

Cardi/ac – pertaining to the heart

Crani/um – portion of the skull that encloses the brain

Gastr/osis – Disease of the stomach

Gastr/algia – pain in the stomach

Gastr/o/dynia – pain in the stomach

Gastr/itis – inflammation of the stomach

Arteri/o/malacia – abnormal softening of the walls of an artery

Hepat/o/megaly – abnormal enlargement of the liver

Arteri/o/necrosis – tissue death of an artery

Arteri/o/sclerosis – abnormal hardening of the walls of an artery

Arteri/o/stenosis – abnormal narrowing of an artery

Suffixes related to Procedures

Abdomin/o/centesis – surgical puncture of the abdominal cavity

Append/ectomy – surgical removal of the appendix

Angi/o/graphy – x-ray study of the blood vessels

Angi/o/gram – film produced by angiography

My/o/plasty – surgical repair of a muscle

Endo/scopy – visual examination of the interior of a body cavity or organ

The Double RRs

There are suffixes, referred to as the “double RRs” which are grouped together in the book to avoid confusion:

Hem/o/rrhage – loss of a large amount of blood

My/o/rrhaphy – to suture a muscle wound

Dia/rrhea – abnormally frequent loose or watery stools

My/o/rrhexis – rupture of a muscle


Pre/nat/al – time and events before birth

Peri/nat/al     time and events surrounding birth (just before, during and after)

Post/nat/al    time and events after birth

Some prefixes are confusing because they are similar in spelling but opposite in meaning.  The more common prefixes of this type are summarized in Table 1.4, page 8.


Ab- away from / ad- toward or in the direction of

Dys- bad, difficult, painful / eu- good, normal well, or easy

Hyper- excessive or increased / hypo- deficient or decreased

Inter- between or among / intra- within or inside

Sub- under, less or below / super-, supra- above or excessive

Tips for Slashing and determining meanings of Medical Words

1.     Always start at the end of the word, with the Suffix and work toward the beginning;

2.     As you separate the word parts, identify the meaning of each.  Identifying the meaning of each part should give you a definition of the term;

3.     Because some word parts have more than one meaning, it also is necessary to determine the context in which the term is being used (i.e., which Body System – more on this in Chapter 2);

4.     Always use a Medical Dictionary to double-check any definition.

Spelling & Pronunciation

Spelling of Medical Terms is very important…. Again, always use a medical Dictionary if you are not sure about the spelling of a Medical term.

Also, a medical term is easier to understand and remember whey you know how to pronounce it properly.  Frequently there may be more than one correct way to pronounce a medical term.  Many Medical terms are based on their Greek, Latin or other origins.  The current trend is to pronounce them as they sound in English.


Abbreviations are frequently used as a shorthand way to record long and complex medical terms.  Appendix B in the back of the book (Page 501) contains an alphabetized list of many of the more commonly used medical abbreviations.

Singular and Plural Endings

Many medical terms have Greek or Latin origins, as previously mentions.  As a result of these different origins, there are unusual rules for changing a singular word into a plural form Table 1.6, Page 11, provides guidelines to help you better understand how these plurals are formed.




If the term ends in a, the plural is usually formed by adding an e



If the term ends in ex or ix, the plural is usually formed by changing the ex or ix to ices



If the term ends in is, the plural is usually formed by changing the is to es



If the term ends in itis, the plural is usually formed by changing the is to ides



If the term ends in nx, the plural is usually formed by changing the x to ges

meninx (tissue)


If the term ends in on, the plural is usually formed by changing the on to a



If the term ends in um, the plural usually is formed by changing the um to a



If the term ends in us, the plural is usually formed by changing the us to i



Sound-alike Medical Terms and Word parts

Just like in the English language, there are commonly used Medical terms that sound alike, but have different meanings:

End/arteri/al – pertaining to the interior or lining of an artery

Ather/oma – fatty deposit within the wall of an artery

Arthr/algia – pain in a joint

-ectomy – surgical removal

-ostomy – surgically create and artificial opening

-otomy – cutting into or a surgical incision

Basic Medical Terms

Table 1.7, Page 12, lists some commonly used Medical Terms used to describe diseases and abnormal conditions:










Table 1.8, Page 15 – lists some common abbreviations for the Elements/Medical words presented in Chapter 1