Medical Terminology Prefixes: Quick Reference and Study Guide

Medical Terminology Prefixes

Introduction

Prefixes are essential components of medical terminology. They are added to the beginning of root words to modify their meaning, often indicating location, time, number, or status. Understanding common prefixes helps students decode complex medical terms and enhances comprehension of medical language.

Common Medical Prefixes and Their Meanings

The following table summarizes frequently used medical prefixes, their definitions, and examples of their application in medical terms.

Prefix	Definition	Example	Meaning of Example
supra-	above; over; beyond	suprarenal	above the kidney
trans-	across; through	transdermal	through the skin
post-	after; behind	postoperative	after surgery
anti-	against	antibiotic	against life (microorganisms)
contra-	against	contraceptive	against conception
pan-	all	pandemic	affecting all people
circum-	around	circumoral	around the mouth
peri-	around; about	pericardium	around the heart
ex-	away from; outside	exhale	breathe out
retro-	backward; behind	retroperitoneal	behind the peritoneum
dys-	bad; difficult; painful; disordered	dysfunction	abnormal function
mal-	bad; poor	malnutrition	poor nutrition
ante-	before; in front	antenatal	before birth
pre-	before; in front	preoperative	before surgery
infra-	beneath; below; under	infrascapular	below the scapula
sub-	beneath; under	subcutaneous	under the skin
inter-	between	intercostal	between the ribs
meta-	beyond; after; change	metastasis	change of place (spread of disease)
ultra-	beyond; excess	ultrasound	beyond sound (high-frequency sound waves)
ambi-	both; both sides	ambidextrous	able to use both hands
de-	down; from	dehydrate	remove water
cata-	down; under; against; lower	catabolism	breakdown of substances
hyper-	excessive; above	hypertension	high blood pressure
pseudo-	false	pseudocyesis	false pregnancy
primi-	first	primigravida	woman pregnant for the first time
quadri-	four	quadriplegia	paralysis of all four limbs
dis-	free of; to undo; double; negative	disinfect	to free from infection
ab-	from; away from; absent	abduct	move away from midline
hemi-	half	hemiplegia	paralysis of one side
semi-	half	semilunar	half-moon shaped
in-	in; inside; within; not	inhalation	breathing in
idio-	individual	idiopathic	of unknown cause (individual to the patient)
sym-, syn-	joined; together	symbiosis, synapse	living together, junction between neurons
mega-	large	megacolon	enlarged colon
bio-	life	biology	study of life
homeo-	likeness; same	homeostasis	state of internal sameness
multi-	many	multicellular	composed of many cells
poly-	many; much	polyuria	excessive urination
meso-	middle	mesoderm	middle layer of embryo
cine-	movement	cineangiography	motion picture recording of blood vessels
juxta-	near; beside	juxtaglomerular	near the glomerulus
para-	near; beside; beyond; two like parts	parathyroid	beside the thyroid
nulli-	none	nullipara	woman who has not given birth
im-, in-, non-	not	impossible, inactive, noninvasive	not possible, not active, not invasive
ana-	not; without; against	anaphylaxis	against protection (allergic reaction)
uni-, mono-	one; single	unilateral, monocyte	one side, single cell
milli-	one-thousandth	milligram	one-thousandth of a gram
ecto-, extra-, exo-	outside; beyond; outward	ectoderm, extracellular, exocrine	outer layer, outside the cell, secreting outward
tachy-	rapid	tachycardia	rapid heart rate
oxy-	rapid; sharp	oxytocin	quick birth (hormone)
rube-	red	rubella	red rash (German measles)
homo-	same	homograft	graft from same species
auto-	self	autoimmune	immune response against self
hypno-	sleep; hypnosis	hypnotic	induces sleep
brady-	slow	bradycardia	slow heart rate
echo-	sound	echocardiogram	ultrasound of the heart
pachy-	thick	pachyderma	thick skin
tri-	three	tricuspid	three cusps (heart valve)
dia-	through; between	dialysis	separation through a membrane
per-	through; intense	percutaneous	through the skin
con-	together; with	congenital	born with
ad-	toward; increase	adduction	movement toward midline
bi-	two; double	bicuspid	two cusps
hypo-	under; below; beneath; less than normal	hypoglycemia	low blood sugar
aniso-	unequal	anisocytosis	unequal cell size
epi-	upon; over; after	epidermis	upon the skin
hydro-	water	hydrocephalus	water in the brain
eu-	well; easily; good; normal	eupnea	normal breathing
alb-	white	albino	absence of pigment
intra-	within	intravenous	within a vein
endo-	within; inner	endoscope	instrument to view inside
an-, a-	without; not; away from	anemia, aseptic	without blood, without infection

Key Points for Studying Medical Prefixes

• Prefixes are attached to the beginning of root words to alter their meaning.

• They often indicate location (e.g., sub- = under), number (e.g., bi- = two), time (e.g., pre- = before), or status (e.g., mal- = bad).

• Some prefixes have similar meanings but are used in different contexts (e.g., anti- and contra- both mean "against").

• Recognizing prefixes can help deduce the meaning of unfamiliar medical terms.

Examples and Applications

• Hypertension: hyper- (excessive) + tension (pressure) = high blood pressure.

• Subcutaneous: sub- (under) + cutaneous (skin) = under the skin.

• Bradycardia: brady- (slow) + cardia (heart) = slow heart rate.

• Intravenous: intra- (within) + venous (vein) = within a vein.

Additional info:

• Some prefixes may change form depending on the root word (e.g., sym- vs. syn-).

• Prefixes can be combined with roots and suffixes to form complex medical terms.