Medical terminology developed largely from Greek and Latin words, so many terms can be deciphered through an understanding of the meanings of various roots and affixes.  This handout illustrates how roots and affixes are used to denote number or size, direction, color, anatomical locations, as well as other meanings.  Medical abbreviations are available from Dr. Julie Stierwalt's Medical Abbreviation Page.

Prefixes and Roots Denoting Number or Size

bi-	two
dipl/o	two, double
hemi-	half
hyper-	over or more than usual
hypo-	under or less than usual
iso-	equal, same
macro-	large
megal/o	enlargement
micro-	small
mono-	one
multi-	many
nulli-	none
poly-	many
semi-	half, partial
tri-	three
uni-	one

Roots Denoting Color

chlor/o	green
cyan/o	blue
erythr/o	red
leuk/o	white
melan/o	black
xanth/o	yellow

Prefixes and Roots Denoting Relative Direction

per-	through
peri-	around
post-	behind, after
poster/o	behind
pre-	before, in front of
pro-	before
retr/o	behind, in back of
sub-	under
super-	beyond
supra-	above
supra--	above
syn-	together
trans-	across
ventr/o	belly

Roots Denoting Anatomical Location

abdomin/o	abdomen
acr/o	extremity
aden/o	gland
angi/o	vessel
arter/i/o	artery
arthr/o	joint
blast/o	embryo
blephar/o	eyelid
bronch/i, bronch/o	bronchus
calcane/o	calaneous
cardi/o	heart
carp/o	carpal, wrist
cephal/o	head
cerebr/o	cerebrum
cheil/o	lip
chol/e	bile, gall
chondr/o	cartilage
cocc/i	coccus
col/o	colon
colp/o	vagina
condyl/o	condyle
core/o, cor/o	pupil
corne/o	cornea
cost/o	ribs
crani/o	cranium
cycl/o	ciliary body
cyst/o	bladder, sac
cyt/o	cell
dactyl/o	fingers or toes
dent/o	tooth
derm/o	skin
dermat/o	skin
duoden/o	duodenum
enter/o	intestine
esophag/o	esophagus
fibr/o	fiber
gangli/o	ganglion
gastr/o	stomach
gingiv/o	gums
gloss/o	tongue
gynec/o	women
hem/o, hemat/o	blood
hepat/o	liver
hidr/o	sweat
humer/o	humerus
hydr/o	water
hyster/o	uterus
ile/o	ileum
irid/o, ir/o	iris
ischi/o	ischium
jejun/o	jejunum
kerat/o	cornea
lacrim/o	tear
laryng/o	larynx
laryng/o	larynx
lip/o	fat
lith/o	stone, calculus
lumb/o	loin, lumbar area
ment/o	chin
my/o	muscle
myel/o	spinal cord, bone marrow
nas/o	nose
nephr/o	kidney
neur/o	nerve
omphal/o	umbilicus, navel
onych/o	nail
oophor/o	ovary
opthalm/o	eye
orchid/o	testicles
oste/o	bone
ot/o	ear
ot/o	ear
pancreat/o	pancreas
pelv/i	pelivs
pelv/i	pelivs
peps/o, peps/ia	digestion
phalang/o	phalange
pharyng/o	pharynx
phas/o	speech
phleb/o	veins
pleur/o	pleura
pne/o	air, breathing
pneum/o, pneumono	lung
pod/o	foot
proct/o	rectum and anus
psych/o	mind
pub/o	pubis
py/o	pus
pyel/o	kidney
rect/o	rectum
ren/o	kidney
retin/o	retina
rhin/o	nose
salping/o	fallopian tube
scler/o	sclera
spermat/o	sperm
splen/o	spleen
stern/o	sternum, breastbone
stomat/o	mouth
thorac/o	thorax, chest
trache/o	trachea
traumat/o	trauma
tympan/o	Eardrum
ur/o	Urine
ureter/o	Ureter
urethr/o	Urethra
vas/o	Vessel
viscer/o	gut, contents of the abdomen

Other Prefixes

a-, an-	without
anti-	against
auto-	self
brady-	slow
con-	with
contra-	against
dis-	free of
dys-	difficult or without pain
mal-	bad, poor
neo-	new
syn-	together
tachy-	fast

Other Roots

necr/o	dead
noct/i	night
par/o	bear
phag/o	eat
phil/o	attraction
plast/o	repair
plast/o	formation
pyr/o	fire, fever
scler/o	tough, hard
sinistr/o	left
syphil/o	syphilis
therap/o	treatment
therm/o	heat
thromb/o	thrombosis
troph/o	development

Other Suffixes

algia	pain
ar	pertaining to
centesis	puncture
clysis	irrigation
ectasia	dilatation, dilation
ectomy	excision
emes/is	vomiting
emia	blood
esthesia	feelings
genesis, gen/o	development, formation, beginning
gnosis	know
ia	noun ending
ia, ic	pertaining to
it is	inflammation
manual	hand
meter	measuring instrument
oid	resembling
ologist	one who studies
ology	study of
oma	tumor
opia	vision
orrhagia	hemorrhage
orrhaphy	suture
orrhea	flow
orrhexis	rupture
osis	condition of
ostomy	new opening
otomy	incision
pedal	foot
pexy	fixing, fixation
phob/ia	fear
plasm	growth
plegia, plegic	paralysis
ptosis	drooping
scope, scopy	examining, looking at
spasm	twitching
sperm	sperm
stasis	slow, stop
tome	instrument
tripsy	crushing