Introduction to
Medical
Terminology
Chapter 1
WORD PARTS ARE THE
KEY!!
• Learning medical terminology
is much easier once you
understand how word parts
work together to form
medical terms.
Three Types of Word Parts:
• Word roots:
• Contain the basic meaning of the
term. They usually, but not
always, indicate the body part.
• Examples: oste/o, neur/o
• They act as the foundation of
most medical terms.
• Suffixes:
• Usually, but not always,
indicate the procedure,
condition, disorder, or
disease. A suffix always
comes at the end of the
word.
• Prefixes:
• Usually, but not always,
indicate location, time,
number or status.
• A prefix always comes at the
beginning of a word.
So….Word Part Guidelines:
• A word root cannot stand alone.
A suffix must be added to
complete the term.
• The rules for use of combining
vowels apply when a suffix is
added to a word root.
• When a prefix is needed, it is
always placed at the beginning.
Combining Vowels
• A combining vowel may be
needed between the word root
and the suffix to make the
medical term easier to
pronounce.
• The letter “o” is the most
commonly used combining
vowel.
• When a word root is shown with
a back slash and a combining
vowel, such as cardi/o, this
format is referred to as the
combining form.
• So…the word root + the
combining vowel = combining
form.
Rules for Using Combining
Vowels:
• A combining vowel is used
when the suffix begins with a
consonant.
• Example: when neur/o is joined
with the suffix –plasty, the
combining vowel is used due to
the consonant. “Neur/o/plasty”
• A combining vowel is not
used when the suffix begins
with a vowel (a,e,i,o,u).
• Example: when neur/o is
combined with the suffix –itis,
the combining vowel is not used,
because the suffix “–itis” begins
with a vowel.
• Word: neur/itis
• A combining vowel is always
used when two or more word
roots are joined.
• Example: When gastr/o is joined
with enter/o, the combining
vowel is used. “gastr/o/enter/o
• But if you add a suffix that starts
with a vowel, you will not use it:
• Word: gastr/o/enter/itis
• A prefix does not require a
combining vowel.
• The prefix is attached directly
onto the word root.
Word Roots Indicating Color
• cyan/o
• = “blue”
• Example:
• cyan/osis = a blue discoloration
of the skin caused by a lack of
adequate oxygen
• cyan + -osis (condition of)
• erythr/o
• = “red”
• Example:
• erythro/cytes = red blood cells.
Erythr = red + “o” for the
combining vowel + cytes (cells).
• leuk/o
• = “white”
• Example:
• leukocytes = leuk (white) + “o”
for the combining vowel + cytes
(cells).
• melan/o
• = “black”
• Example:
• melanoma = melan/o + the
suffix “-oma” (tumor)
• Note: the combining vowel was
dropped since the suffix begins
with a vowel.
• poli/o
• = “gray”
• Example:
• Poli/o/myel/itis – an inflammation of
the gray matter of the spinal cord
usually causing paralysis.
• Note: the combining vowel was used
to connect the word roots but
dropped from myel/o to join it with –
itis.
Let’s talk about suffixes….
• Suffixes usually, but not always,
indicate the procedure,
condition, disorder or disease:
• Examples: tonsill/o = tonsils.
Tonsill + -itis (inflammation) =
tonsillitis
• Tonsill/o + -ectomy (surgical
removal) = tonsillectomy
• Some suffixes complete the term
by changing the word root into
an adjective. Many of these
suffixes are defined as
“pertaining to”.
• Most common: -al, -ic, -ac
• Examples: cardi/ac, gastr/ic,
enter/al.
• Some suffixes complete the term
by changing the word root into a
noun.
• Example: “-um” is a noun
ending.
• Crani/um = “crani” means
skull, and “-um” is a noun
ending.
• Cranium is the portion of the
skull that surrounds the brain.
• Some suffixes have a general
meaning of “abnormal
condition”.
• For example, -osis means an
abnormal condition.
• “Gastrosis” means any abnormal
condition of the stomach.
• Gastr/o = stomach; -osis =
abnormal condition.
• Pathology means the study of
disease and the suffixes related
to pathology describe specific
disease conditions.
• These suffixes will repeat each
chapter, so you must learn them
in order to build words for each
body system.
• -algia means “pain”. Example:
gastr/algia = stomach pain.
Note: the combining vowel was
not used: suffix starts with vowel
• -dynia also means “pain”.
Example: gastr/o/dynia =
stomach pain. Notice, the
combining vowel was used since
the suffix begins with a
consonant.
• -itis means “inflammation”.
• Example: gastr/itis means
inflammation of the stomach.
• Note: the combining vowel was
dropped from gastr/o since
“-itis” begins with a vowel.
• Another example we saw in a
previous slide: tonsill/itis.
• -malacia means “abnormal
softening.”
• Example: crani/o/malacia =
abnormal softening of the skull.
• crani = skull + “o” + -malacia
• Note: the combining vowel was
used because the suffix begins
with a consonant.
• -megaly means “enlarged” or
enlargement of.
• Example: hepat/o/megaly
• hepat/o means “liver”
• -megaly means “enlarged”
• so….hepat/o/megaly means
“enlarged liver”.
• To make it easy, remember that
“mega” means big, large.
• -necrosis means “tissue
death”.
• Example: arteri/o/necrosis
• means “death of tissue of an
artery”
• arteri/o = artery; -necrosis =
death of tissue
• Note: combining vowel was used
since the suffix begins with a
consonant.
• -sclerosis means “abnormal
hardening” (is the opposite of
–malacia).
• Example: arteri/o/sclerosis
• means “abnormal hardening of
the arteries”
• Note: combining vowel was used
since the suffix begins with a
consonant.
• -stenosis means “abnormal
narrowing”
• Example: arteri/o/stenosis
means “abnormal narrowing of
the arteries”
• arteri/o = arteries; -stenosis =
abnormal hardening.
• Note: combining vowel was
used. Why?
• Some suffixes identify a
procedure that is performed on
the body part identified by the
word part.
• Again, these suffixes are the
building blocks for word used in
each of the chapters, so learn
them as quickly as possible.
• -centesis means “surgical
puncture to remove fluid”.
• Example: abdomin/o/centesis
• Means “a surgical puncture of
the abdominal cavity to remove
fluid.”
• abdomin/o = abdomen; centesis = surgical puncture.
• -ectomy means “surgical
removal of”.
• Example: tonsill/ectomy =
surgical removal of tonsils.
• append/ectomy = surgical
removal of the appendix.
• The combining vowel would
never be used with –ectomy
since it starts with a vowel.
• -graphy means “the process of
recording a picture or
record.”
• Example: mamm/o/graphy = the
process of taking a picture
(x-ray) of the breast.
• -gram means “the picture or
record itself”.
• Example: mamm/o/gram = the
picture (x-ray) of the breast.
• -ostomy means “to surgically
create an artificial opening”.
• Example: col/ostomy = the
surgical creation of an opening
between the colon and the body
surface. Col/o = colon.
• To remember this suffix, think of
“os” as a word that means
“opening”.
• -otomy means “surgical
incision, or cutting into”.
• Example: col/otomy = surgical
incision into the colon.
• Splen/otomy = surgical incision
into the spleen.
• Arteri/otomy = surgical incision
into an artery.
• -plasty means “surgical
repair”.
• Example: my/o/plasty = surgical
repair of a muscle.
• my/o = muscle; -plasty =
surgical repair.
• abdomin/o/plasty = surgical
repair of the abdomen.
• -scopy means “visual
examination of a body cavity
or organ by use of a scope”
• Example: arthr/o/scopy
• Means visual examination of a
joint using a scope.
• arthr/o = joint; -scopy = using a
scope for visual examination.
The Double RRs
• Suffixes beginning with two Rs
are particularly confusing.
• -rrhage and –rrhagia =
abnormal excessive fluid
discharge or bleeding.
• Example: hem/o/rrhage is the
loss of a large amount of blood
in a short time.
• -rrhaphy means “to suture or
stitch”.
• Example: my/o/rrhaphy = suture
a muscle.
• my/o = muscle; -rrhaphy =
suture.
• To remember this suffix, think of
r-r-wrap as if you were going to
wrap the injury in sutures.
• -rrhea means “an abnormal
flow or discharge”. Refers to
the abnormal flow of most body
fluids.
• Example: diarrhea = abnormally
frequent loose or watery stools.
• Dia- means “through”, and
–rrhea means “abnormal flow”.
• -rrhexis means “rupture.”
• Example: my/o/rrhexis =
rupture of a muscle.
• My/o = muscle; -rrhexis =
rupture.
• To remember this suffix, think of
the x as being ready to rupture
and fly apart.
Suffixes relating to “study”
• -ology means “the study of”.
• Example: neur/ology is the study
of the nerves.
• Cardi/ology is the study of the
heart.
• -ologist means “the specialist
who studies”.
• Example: neur/ologist =
specialist who studies nerves.
• Cardi/ologist = specialist who
studies the heart.
• Hepat/ologist = specialist who
studies the liver.
Now, let’s look at prefixes….
• A prefix is added to the
beginning of a word to change
the meaning of that term.
• Prefixes usually, but not always,
indicate location, time, or
number.
Common Prefixes:
• pre- means “before”.
• Example: pre/natal = before
birth
• post- means “after”.
• Example: post/natal = after the
birth.
• dys- means “bad, difficult, or
painful”.
• Example: dys/uria = difficult or
painful urination.
• eu- means good, normal,
well, or easy. The opposite of
dys-.
• Example: eu/thyroid = a
normally functioning thyroid
gland.
• hyper- means “excessive or
increased”.
• Example: hyper/tension means
higher than normal blood
pressure.
• hypo- means “deficient or
decreased”. Opposite of hyper-.
• Example: hypo/tension is lower
than normal blood pressure.
• inter- means “between or
among”.
• Example: inter/costal means
between the ribs (cost/o = ribs).
• intra- means within or inside.
• Example: intra/muscular means
within the muscle.
• sub- means “under, less, or
below”.
• Example: sub/costal = below the
ribs.
• supra- means “above or
excessive”. Opposite of sub-.
• Example: supra/costal = above
or outside the ribs.
Determining Meanings on
the Basis of Word Parts
• To find a word’s meaning, you
must first separate it into word
parts.
• You can do this by using slash
marks (/) to separate them.
• Example: tonsill/ectomy
• Always start at the end of the
word, with the suffix, and work
toward the beginning.
• Example: tonsill/ectomy =
surgical removal of the tonsils.
• As you separate the word parts,
this should give you a definition
of the term.
• Because some word parts have
more than one meaning, it also
is necessary to determine the
context in which the term is
being used. As used here,
context means to determine
which body system this term is
referring to.
• If you have any doubt, use your
medical dictionary to doublecheck the definition.
• Taber’s Medical Dictionary is the
one used in this classroom, and
in most healthcare facilities.
Using a Medical Dictionary
• When starting to work with an
unfamiliar dictionary, spend a
few minutes reviewing its use
guide, table of contents, and
appendices.
• If you cannot find the word on
the basis of your spelling, start
looking for alternative spellings
based on the beginning sounds.
• Open your book to page 10.
• Look at Table 1.5 at the bottom
of the page.
• Let’s go over these…..
• Then, close your book again.
Rules to remember…..
• Frequently, there is more than
one correct way to pronounce a
medical term.
• Example: arthroscopy or
arthroscopy
• Both are correct; the difference
is a matter of preference.
• Correct spelling is extremely
important!
• Changing just one or two letters
can completely change the
meaning of a word – and this
difference literally could be a
matter of life or death for the
patient.
• Abbreviations are frequently
used as a shorthand way to
record long and complex medical
terms.
• But they can also lead to
confusion and errors!
• Be very careful when using or
translating an abbreviation.
• Example: BE means “below
elbow” and “barium enema”!
• Because the same abbreviation
may have more than one
meaning, it is important that you
be very careful when using or
translating an abbreviation.
• To be safe, always follow this
rule:
• When in doubt, spell it out!
Singular and Plural Endings
• Many medical terms have Greek
or Latin origins. As a result of
these different origins, there are
unusual rules for changing a
singular word into a plural form.
• Turn to page 12 in your book.
• Let’s go over these guidelines.
Basic Medical Terms
• Let’s look over at page 13 in
your textbook to learn some
similar and opposite terms.
Study Break
• Turn to page 15; look at the
orange box at the bottom titled
“Study Break.”
• That ends this chapter!!!!