HESI A2 Vocabulary study guide

How a word's meaning is decided by its sentence: the five context clues, the prefix-root-suffix system with a combining vowel, tables of the parts health care actually uses, irregular plurals, confusable pairs, and the general and health-care word lists this topic draws on.

What this topic actually asks of you

Vocabulary on this exam asks what a word means, and the work splits in two directions: reading a word from its context, and taking a long medical word apart into the pieces a health-care vocabulary is built from.

Elsevier lists vocabulary among the areas the HESI A2 covers. The publisher releases no national content specification — no item count, no clock, no cut score — so nothing on this page mirrors an official weighting, and nothing here claims to. What this page offers is a word-part system and a word list: the prefixes, roots and suffixes that build terms, and a plain-English list of the general and health-care words a passage is likely to use, each with its own example sentence.

The word parts follow the US National Library of Medicine's consumer guide to medical words; the definitions are standard meanings written for this course, with no dictionary text copied, and every example sentence is ours.

The nine ideas this page teaches

Context clues — the six ways a sentence tells you what a word means.
How a medical word is built — prefix, then root, then suffix, with a combining vowel when the suffix starts with a consonant.
Prefixes of position, size and speed — the largest group, and the one that changes a word's direction.
Roots — the body part or the substance the word is about.
Suffixes — what is being done, and whether the word names a condition, a procedure or a specialist.
Plurals of medical words — the endings that do not simply add an s.
Confusable pairs — affect and effect, accept and except, and the rest of the pairs that look alike.
Academic and health-care words — the general vocabulary of a passage about care, risk and outcome.
Deriving an unknown word — what to do when a term is not on this page.

Context clues: six ways a sentence tells you

Clue	What the sentence does	Example
Context clue: definition	a direct statement of the meaning, often in an appositive after a comma or a dash	"The patient was afebrile — no fever at all — for three days."
Context clue: restatement	a rewording in ordinary words nearby, set off by commas or a dash, that adds no new information	"The wound was superficial, involving only the top layer of skin."
Context clue: contrast	supplies the opposite, so the word must be its reverse	"The first dose was benign in its effects, unlike the second, which caused a rash."
Context clue: example	lists instances, and the word names the category	"Vital signs such as pulse, blood pressure and temperature were recorded hourly."
Context clue: cause and effect	the word's consequence is stated	"Because the dressing was occlusive, it sealed the air out and the wound stayed moist."
Context clue: general sense	the sentence's tone and subject narrow the meaning	"The second reader would concur with the opinion, so the plan did not change."

The test for a context answer is a substitution: put your meaning back into the sentence and read it again. If the sentence still says something a nurse would say, the meaning fits. If it says something odd, the sense is wrong even when the word's dictionary meaning is right.

How a medical word is built

A medical term is assembled in a fixed order, and the order is the meaning.

prefix + root + suffix — as in bradycardia: brady- (slow) + card (heart) + -ia (condition), so a slow heart rate.

Piece	What it contributes	Where it sits	Example
prefix	position, number, size, speed, or a negation	at the front	tachy- in tachycardia, a fast heart rate
root	the body part or substance the word is about	in the middle	gastr- in gastritis, inflammation of the stomach
combining vowel	usually o, joining a root to a suffix that starts with a consonant	between root and suffix	o in gastroscopy, so the parts do not collide
suffix	the condition, procedure, or kind of specialist	at the end	-itis in gastritis, meaning inflammation

Three rules make the system usable.

Read a long word from the suffix back to the prefix. The suffix says what kind of thing the word is, the root says where, and the prefix says how.
Keep the combining vowel only when the suffix begins with a consonant. gastr-o-scopy takes the o because -scopy starts with a consonant; gastr-itis drops it because -itis starts with a vowel.
Do not read a prefix as a word of its own. -ia at the end of bradycardia is the suffix that names a condition, not the prefix a- that means "without". The same letters, in different positions, are different pieces.

Prefixes: position, size, speed, number, negation

Learn the prefixes by what they do to a word's direction, not as a list of letters. Each one below is a piece of a word you will meet in a health-care passage.

Position

Prefix	Meaning	Word, and what it means
ante-	before	antepartum — the period before birth
pre-	before	preoperative — before a procedure
post-	after	postoperative — after a procedure
peri-	around	pericardium — the sac around the heart
circum-	around	circumcision — a cutting around
sub-	under, below	subcutaneous — under the skin
infra-	below	infrared — below red on the spectrum
supra-	above	suprapubic — above the pubic bone
epi-	on, over	epidermis — the layer over the dermis
endo-	within	endocrine — secreting within the body
intra-	inside	intravenous — inside a vein
inter-	between	intercostal — between the ribs
extra-	outside	extracellular — outside the cell
trans-	across, through	transdermal — through the skin
retro-	backward, behind	retroperitoneal — behind the peritoneum
ab-	away from	abduction — movement away from the midline
ad-	toward	adduction — movement toward the midline

Size, speed and amount

Prefix	Meaning	Word, and what it means
brady-	slow	bradycardia — a slow heart rate
tachy-	fast	tachypnea — fast breathing
macro-	large	macrophage — a large cell that engulfs debris
micro-	small	microcyte — a small red blood cell
mega-	very large	megacolon — an abnormally wide colon
hyper-	above normal	hypertension — high blood pressure
hypo-	below normal	hypotension — low blood pressure
oligo-	few, scanty	oliguria — scanty urine output
poly-	many, much	polyuria — excessive urine output
eu-	normal, good	eupnea — normal breathing
neo-	new	neonate — a newborn

Number

Prefix	Meaning	Word, and what it means
mono-, uni-	one	mononucleosis, unilateral — one side
bi-, di-	two	bilateral — both sides
tri-	three	tricuspid — a valve with three flaps
quadri-	four	quadriplegia — loss of function in all four limbs
hemi-	half	hemiplegia — loss of function on one side
semi-	half	semicircular — half a circle, as in the ear's canals

Negation and absence

Prefix	Meaning	Word, and what it means
a-, an-	without	afebrile — without fever; anemia — without sufficient blood
anti-	against	antibiotic — against bacteria
contra-	against	contraindication — a reason against a treatment
de-	down, away from	dehydration — loss of water
dis-	apart, not	dislocation — displacement of a joint
mal-	bad, abnormal	malnutrition — poor nutrition
dys-	difficult, abnormal	dyspnea — difficult breathing

Two prefixes are worth a warning because they look like ordinary words. Hyper- and hypo- differ by one letter and mean opposite things — a hyperglycemic patient is high, a hypoglycemic patient is low, and confusing them is a clinical error, not a vocabulary slip. Dys- means difficult or abnormal, not absent: dysuria is painful urination, anuria is none.

Roots: the body part inside the word

Root	Means	Word, and what it means
cardi-	heart	cardiology — the study of the heart
pulmon-, pneum-	lung, air	pulmonary — relating to the lungs; pneumonia — an infection of the lung
gastr-	stomach	gastrectomy — removal of the stomach
hepat-	liver	hepatomegaly — an enlarged liver
nephr-	kidney	nephritis — inflammation of a kidney
ren-	kidney	renal — relating to the kidney
cyst-	bladder, sac	cystoscopy — viewing inside the bladder
enter-	intestine	enteritis — inflammation of the intestine
col-, colon-	colon	colostomy — an opening into the colon
arthr-	joint	arthritis — inflammation of a joint
oste-	bone	osteoporosis — bone that has thinned and weakened
my-, myo-	muscle	myalgia — muscle pain
derm-, dermat-	skin	dermatitis — inflammation of the skin
neur-	nerve	neurology — the study of the nervous system
encephal-	brain	encephalitis — inflammation of the brain
cerebr-	brain	cerebral — relating to the cerebrum
hem-, hemat-	blood	hematocrit — the proportion of blood that is red cells
vas-, vascul-	vessel	vascular — relating to blood vessels
therm-	heat	thermometer — an instrument for measuring heat
glyc-	sugar	glycemia — the sugar level in the blood
lip-	fat	lipids — fats and fat-like substances
cutane-	skin	cutaneous — relating to the skin
cost-	rib	intercostal — between the ribs
thorac-	chest	thoracic — relating to the chest
abdomin-	abdomen	abdominal — relating to the abdomen
hist-	tissue	histology — the study of tissue

Roots come in two spellings more often than the table suggests, and both spellings mean the same thing: nephr- and ren- are both kidney, pneum- and pulmon- are both lung, encephal- and cerebr- are both brain. Either spelling in a word tells you the organ; the rest of the word tells you what is happening to it.

Suffixes: what is being done, and to what kind of word

The suffix tells you what kind of thing the word is — a condition, an inflammation, a procedure, a specialist, or a record. Read it first.

Conditions and processes

Suffix	Means	Word, and what it means
-itis	inflammation	gastritis — inflammation of the stomach
-osis	a condition, often abnormal	osteoporosis — a condition of thinned bone
-iasis	a condition, often caused by something	cholelithiasis — the presence of gallstones
-pathy	disease	neuropathy — disease of a nerve
-emia	a condition of the blood	anemia — a shortage of red cells or hemoglobin
-uria	a condition of the urine	hematuria — blood in the urine
-oma	a tumor or swelling	hematoma — a swelling of clotted blood
-megaly	enlargement	cardiomegaly — an enlarged heart
-plegia	paralysis	paraplegia — loss of function in the lower limbs
-pnea	breathing	dyspnea — difficult breathing
-rrhea	flow, discharge	diarrhea — a flow of loose stool
-spasm	an involuntary contraction	bronchospasm — a tightening of the airways
-stenosis	narrowing	arteriostenosis — a narrowing of an artery
-edema	swelling from fluid	lymphedema — swelling from lymph that cannot drain

Procedures, records and specialists

Suffix	Means	Word, and what it means
-scopy	viewing with an instrument	endoscopy — viewing the inside of a tract
-ectomy	surgical removal	appendectomy — removal of the appendix
-otomy	a cutting into	tracheotomy — a cutting into the windpipe
-ostomy	a surgical opening	colostomy — an opening from the colon to the surface
-plasty	repair, reshaping	angioplasty — repair of a blood vessel
-rrhaphy	suturing	herniorrhaphy — suturing a hernia
-centesis	a puncture to draw fluid	amniocentesis — sampling amniotic fluid
-gram	a record or image	electrocardiogram — a record of the heart's electrical activity
-graphy	the process of recording	radiography — imaging with radiation
-meter	an instrument for measuring	spirometer — an instrument that measures lung volumes
-logy	the study of	hematology — the study of blood
-logist	a specialist in	oncologist — a specialist in cancer care
-algia	pain	arthralgia — joint pain
-ic, -al, -ary	relating to	cardiac, renal, pulmonary — relating to the heart, kidney, lungs
-ous	full of, having	mucous — producing mucus

Two pairs are easy to mix and worth naming. -ectomy removes, -otomy cuts into, -ostomy makes a new opening that stays; the three words differ in what happens to the tissue afterwards. -gram is the record, -graph is the instrument that makes it, -graphy is the process — a cardiogram is the tracing, a cardiograph is the machine.

Plurals: the endings that do not take an s

Medical words keep the plural of the language they were borrowed from, so the plural is learned with the word itself. The pattern is regular once you know it.

Singular ending	Plural ending	Example
-a	-ae	vertebra → vertebrae
-us	-i	bronchus → bronchi; stimulus → stimuli
-um	-a	bacterium → bacteria; atrium → atria
-on	-a	criterion → criteria
-is	-es	diagnosis → diagnoses; crisis → crises
-ix, -ex	-ices	appendix → appendices; cortex → cortices

The rule of thumb: if the word ends in -is, the plural is -es and the vowel changes; if it ends in -um, the plural is -a. The plural of analysis is analyses, not analysises, and the plural of datum is data, which is why "the data show" is correct in careful writing even though "the data shows" is common in speech.

Confusable pairs: the words that cost the easiest point

These are pairs a question can test without any medical content at all, and a passage can turn on one of them. The right-hand column is the test that separates them; Grammar takes the usage rules further.

Pair	The distinction	The test
affect / effect	affect is usually a verb (to influence); effect is usually a noun (a result)	if you can put "the" in front of it, it is effect
advice / advise	advice is the noun; advise is the verb	"she gave me ___" takes the noun
breath / breathe	breath is the noun; breathe is the verb	"to ___" takes the verb
accept / except	accept means to receive; except means to leave out	"everyone ___ one" needs except
conscious / conscience	conscious means awake or aware; conscience is the sense of right and wrong	"the patient was ___" (awake) takes conscious; "a guilty ___" takes conscience
complement / compliment	complement completes; compliment praises	a full set complements; a nice remark compliments
discreet / discrete	discreet means tactful; discrete means separate	separate items are discrete
elicit / illicit	elicit means to draw out; illicit means unlawful	a response is elicited
eminent / imminent	eminent means distinguished; imminent means about to happen	a risk that is about to happen is imminent
ensure / insure	ensure means to make certain; insure means to cover by insurance	"___ that the door is locked" takes ensure
loose / lose	loose means not tight; lose means to no longer have	"did not ___ the chart" takes lose
precede / proceed	precede means to come before; proceed means to go on	the step that comes first precedes
principal / principle	principal means main, or a leading person; principle is a rule or belief	"the ___ reason" takes principal
stationary / stationery	stationary means not moving; stationery is paper and envelopes	a patient who does not move is stationary
than / then	than compares; then marks time	a comparison takes than
their / there / they're	possession / place / "they are"	substitute "they are" and see if the sentence survives

The general words a passage uses

These are the words that carry a passage's argument rather than its subject. Each is defined in one line and used in a sentence this course wrote.

Word	Means	In a sentence
acute	sharp, severe, or of short duration	The acute pain subsided within an hour of the dose.
adequate	enough for the purpose	An adequate supply of gloves was kept at every station.
adverse	harmful, unfavorable	The adverse reaction was reported the same day.
ambiguous	open to more than one reading	The order was ambiguous, so the nurse repeated it back.
chronic	long-lasting, persisting	Chronic conditions need review at every visit.
compensate	to make up for a loss or a defect	The body compensates for the blood loss by narrowing vessels.
comply	to act in line with a rule or request	The unit complied with the new hand-hygiene policy.
concur	to agree	The second clinician would concur with the diagnosis once the scan was read.
consequence	a result that follows	A consequence of the delay was a longer stay.
consistent	the same each time, without contradiction	Her notes were consistent across all three visits.
deteriorate	to become worse	The patient's breathing deteriorated overnight.
distinguish	to tell one thing from another	Distinguish a faint pulse from no pulse before starting compressions.
exacerbate	to make worse	Cold air exacerbates the cough.
facilitate	to make easier	A checklist facilitates the handover between shifts.
imply	to suggest without stating	The note implies the dressing was changed, but does not say so.
infer	to conclude from evidence	From the chart you can infer that the dose was doubled.
minimal	the least possible in the circumstances	Movement was kept to a minimal level.
monitor	to watch over time	Monitor the site for redness every four hours.
predispose	to make more likely in advance	A long stay predisposes a patient to weakness.
prevalent	common in a place or group	The condition is more prevalent in older adults.
prohibit	to forbid	The policy prohibits reusing a single-use needle.
reluctant	unwilling	The patient was reluctant to describe the pain.
residual	what remains	A residual cough persisted for a week.
subsequent	coming after	A subsequent test confirmed the first result.
sufficient	enough	Sufficient fluid intake was recorded on the chart.
symptomatic	showing signs of a condition	She remained symptomatic for two days.
tolerate	to endure without serious harm	He tolerated the medication without nausea.
unremarkable	within normal limits	The abdominal exam was unremarkable.
vital	necessary to life, or essential	Vital signs were recorded on admission.
withhold	to hold back deliberately	The dose was withheld until the blood pressure was checked.

The health-care terms a passage assumes you know

These are terms a reading passage may use without defining, because the writer expects a health-care student to have met them. The definition is the plain meaning; the sentence is ours.

Term	Means	In a sentence
afebrile	without fever	The child was afebrile by the second morning.
ambulatory	able to walk; not bed-bound	The patient was ambulatory by the third day.
bolus	a single dose given at once; also a mass of chewed food ready to swallow	The bolus was given over two minutes.
contusion	a bruise	A contusion spread across the forearm.
cyanosis	a blue-gray tint from low oxygen	Cyanosis at the lips prompted an immediate oxygen check.
diaphoresis	heavy sweating	Diaphoresis accompanied the drop in blood pressure.
distention	swelling from internal pressure	Abdominal distention was noted after the meal.
dysphagia	difficulty swallowing	Dysphagia put the patient on a soft diet.
emesis	vomiting	Emesis followed the second dose.
febrile	having a fever	The patient remained febrile through the night.
flatus	gas passed from the bowel	Passing flatus was the sign the bowel had resumed.
hematemesis	vomiting blood	Hematemesis was reported to the clinician at once.
idiopathic	of unknown cause	The diagnosis was idiopathic, meaning no cause was found.
incontinence	loss of control over urine or stool	Incontinence was recorded at each check.
intubate	to place a tube in the airway	The team chose to intubate before the transfer.
laceration	a cut	The laceration was cleaned and closed.
lethargy	unusual drowsiness and low energy	Lethargy in an older patient is a warning sign.
malaise	a general feeling of being unwell	Malaise was the only symptom reported.
necrosis	death of tissue	Necrosis at the wound edge required review.
orthopnea	breathlessness when lying flat	Orthopnea led her to sleep propped up.
pallor	unusual paleness	Pallor and cool skin suggested poor circulation.
pruritus	itching	Pruritus spread across the chest and back.
purulent	containing pus	The drainage turned purulent by day four.
rales	crackling sounds heard in the lungs	Rales were heard at both bases.
syncope	fainting	Syncope on standing was reported twice.
vertigo	a sense of spinning	Vertigo made the walk to the bathroom unsafe.
void	to pass urine	The patient voided within an hour of surgery.

Deriving a word that is not on this page

Most terms a passage uses are not in any list, including this one. Four steps will get you a working meaning.

Take the suffix first. It tells you what kind of word this is: a condition (-itis, -osis), a procedure (-ectomy, -scopy), a specialist (-logist), or a description (-ic, -al).
Find the root. It names the part or the substance. Where two roots appear, the first usually names a part and the second the thing done or found there, as in gastr-o-enter-itis — stomach and intestine, both inflamed.
Read the prefix last. It changes direction or degree: sub- under, hyper- above, brady- slow, poly- many.
Check the whole against the sentence. A derived meaning that contradicts the sentence is wrong, and the sentence wins. Context is the final test, not the parts.

Worked example: pericardiocentesis. Suffix -centesis — a puncture to draw fluid. Root cardi — heart. Prefix peri- — around. So: a puncture into the sac around the heart to draw off fluid. A sentence saying "the fluid was sent for culture" confirms the reading; a sentence saying the patient was given a tablet would not, and the sentence would overrule the parts.

The list, in one place

Every word part this page teaches, alphabetized, with no example word and no explanation beside it. The point of the plain version is that it can be drilled: cover the middle column, read the part, say what it does, and uncover. A part you can say cold is a part you will read correctly inside a word you have never seen; a part you can only recognize in the example word it was taught with has not been learned yet.

96 parts is not a memorization project to finish in one sitting. Three passes of ten minutes, a day apart, with the third pass done from the part alone, moves more than an hour of re-reading the tables above.

The parts are not the whole vocabulary section: a 150-word list of the words this course teaches covers the general, health-care and science terms that are used rather than dissected.

Word part	Means	Kind
a-, an-	without	prefixes
ab-	away from	prefixes
abdomin-	abdomen	roots
ad-	toward	prefixes
-algia	pain	suffixes
ante-	before	prefixes
anti-	against	prefixes
arthr-	joint	roots
bi-, di-	two	prefixes
brady-	slow	prefixes
cardi-	heart	roots
-centesis	a puncture to draw fluid	suffixes
cerebr-	brain	roots
circum-	around	prefixes
col-, colon-	colon	roots
contra-	against	prefixes
cost-	rib	roots
cutane-	skin	roots
cyst-	bladder, sac	roots
de-	down, away from	prefixes
derm-, dermat-	skin	roots
dis-	apart, not	prefixes
dys-	difficult, abnormal	prefixes
-ectomy	surgical removal	suffixes
-edema	swelling from fluid	suffixes
-emia	a condition of the blood	suffixes
encephal-	brain	roots
endo-	within	prefixes
enter-	intestine	roots
epi-	on, over	prefixes
eu-	normal, good	prefixes
extra-	outside	prefixes
gastr-	stomach	roots
glyc-	sugar	roots
-gram	a record or image	suffixes
-graphy	the process of recording	suffixes
hem-, hemat-	blood	roots
hemi-	half	prefixes
hepat-	liver	roots
hist-	tissue	roots
hyper-	above normal	prefixes
hypo-	below normal	prefixes
-iasis	a condition, often caused by something	suffixes
-ic, -al, -ary	relating to	suffixes
infra-	below	prefixes
inter-	between	prefixes
intra-	inside	prefixes
-itis	inflammation	suffixes
lip-	fat	roots
-logist	a specialist in	suffixes
-logy	the study of	suffixes
macro-	large	prefixes
mal-	bad, abnormal	prefixes
mega-	very large	prefixes
-megaly	enlargement	suffixes
-meter	an instrument for measuring	suffixes
micro-	small	prefixes
mono-, uni-	one	prefixes
my-, myo-	muscle	roots
neo-	new	prefixes
nephr-	kidney	roots
neur-	nerve	roots
oligo-	few, scanty	prefixes
-oma	a tumor or swelling	suffixes
-osis	a condition, often abnormal	suffixes
oste-	bone	roots
-ostomy	a surgical opening	suffixes
-otomy	a cutting into	suffixes
-ous	full of, having	suffixes
-pathy	disease	suffixes
peri-	around	prefixes
-plasty	repair, reshaping	suffixes
-plegia	paralysis	suffixes
-pnea	breathing	suffixes
poly-	many, much	prefixes
post-	after	prefixes
pre-	before	prefixes
pulmon-, pneum-	lung, air	roots
quadri-	four	prefixes
ren-	kidney	roots
retro-	backward, behind	prefixes
-rrhaphy	suturing	suffixes
-rrhea	flow, discharge	suffixes
-scopy	viewing with an instrument	suffixes
semi-	half	prefixes
-spasm	an involuntary contraction	suffixes
-stenosis	narrowing	suffixes
sub-	under, below	prefixes
supra-	above	prefixes
tachy-	fast	prefixes
therm-	heat	roots
thorac-	chest	roots
trans-	across, through	prefixes
tri-	three	prefixes
-uria	a condition of the urine	suffixes
vas-, vascul-	vessel	roots

Sort order is alphabetical on the part itself, so -algia sits among the a's regardless of the dash and -ectomy among the e's. Where two spellings mean the same thing — nephr- and ren-, mono- and uni- — they are one line, because the exam will not ask you which spelling is more correct.

The traps, collected

The trap	What it looks like	The fix
Common mistake: picking the most familiar meaning	Wrong: practice read as "rehearse" in a clinical passage	substitute the choice back into the sentence
Common mistake: ignoring the part of speech	Wrong: effect chosen where the sentence needs a verb	decide which word class the blank needs first
Common mistake: reading half the prefix	Wrong: hypo- read as hyper-	read the prefix to its last letter; they mean opposites
Common mistake: taking a word part out of order	Wrong: the -ia of bradycardia read as the a- of apnea, so the last piece is taken for the first and the root is skipped	read suffix back to prefix: brady- (slow) + cardi (heart) + -ia (condition)
Common mistake: trusting a near-synonym	a choice that is close but shifts the degree	ask whether the sentence says "a lot" or "a little"
Common mistake: assuming one spelling per root	Wrong: nephr- missed because the word says renal	learn the root pairs, not single spellings
Common mistake: dropping the combining vowel wrongly	Wrong: gastritis read as gastr-o-itis	the vowel is dropped before a vowel-initial suffix
Common mistake: choosing a true statement that does not answer	the choice defines the word but not its sense here	answer the sentence's question, not the dictionary's

How to practice this

Build ten words a day from parts. Take a suffix from this page and a root, add a prefix, and write the meaning before you look it up. Ten a day is seventy a week, and the same parts come round again.
Keep a context notebook. When a word stops you, write the sentence down, not just the word. The sentence is what you will recognize next time.
Drill the pairs aloud. Affect and effect are separated by a frame rather than a definition: say "the effect" and "to affect" until the frame is automatic.
Read one label a day. A medication label or an instruction sheet gives you real sentences with real terms, and the same terms appear on the next label.
Test yourself backwards. Given a meaning, produce the word. Recognition is what a passage question asks for, but producing the word is what proves you know it.

Where to go next

The subject's own page — Vocabulary lists what is published for this subject, including its guide and its practice set as they land.
The sentences these words sit in — Grammar: agreement, punctuation and the errors that make a clear word ambiguous.
Reading a passage that uses them — Reading Comprehension: the method for finding the one line that answers a question.
The science behind the roots — Biology and Chemistry: the body systems and the substances these terms name.

Sources. The prefix, root and suffix lists follow the US National Library of Medicine's consumer guidance on understanding medical words (medlineplus.gov), US federal government material that is not subject to copyright in the United States; the word parts and their meanings are standard medical terminology and are given here in our own words. The plural patterns follow the same guidance and standard English usage. Every definition, example sentence and table on this page was written for this course; no dictionary or glossary text is reproduced. The publisher's own account of the areas the exam covers is quoted from its HESI A2 page. Accessed 2026-10-27.

HESI A2 is a trademark of Elsevier Inc. Elk Ridge Academy is an independent study resource and is not affiliated with, endorsed by, or sponsored by Elsevier Inc. Exam names are used descriptively only.