150 words this course teaches for the HESI A2 vocabulary section — 70 general academic words, 45 health-care terms and 35 science and math words, each with a one-line meaning, plus a three-pass way to drill the list.

The 150-word vocabulary list

Vocabulary is one of the academic areas Elsevier names, and the publisher releases no word list for it — no official list of words the section will use, no count, no weighting. So this page does not pretend to be the list. It is a list of 150 words this course teaches, chosen because they carry the meaning of a passage about health rather than the subject of one, grouped into general academic words, health-care terms and the science words a science passage assumes, with a one-line meaning beside each.

Two things make the list usable rather than decorative. Each meaning is short enough to be said aloud in one breath, so the list can be drilled by covering a column. And the words are not the word parts: recognizing -itis is a different skill from knowing what pruritus means, and a passage can put either in front of you. The word-part system — prefix, root, suffix — is taught in the vocabulary guide, which is where the long medical words are taken apart.

How to read the list

The meaning is one sense, not every sense. A word with several meanings is glossed for the sense a health-care passage uses, because that is the sense the passage will be building on.
A gloss is not a definition to memorize in isolation. The moment a word appears in a sentence, the sentence narrows it: see the six context clues in the guide. The list is where recognition starts, not where it ends.
Group C is not a chemistry course. Those words appear in science and math passages as vocabulary — gradient, equilibrium, dilution — and the chemistry behind them is on the chemistry guide.

A. General and academic words (70)

These carry a passage's argument rather than its subject. A question built on one of them is testing whether you followed the reasoning, not whether you know the topic.

Word	Means	Word	Means
abstract	existing as an idea rather than a thing	accurate	correct in every detail
adapt	to change to fit a new condition	adjacent	next to
advocate	to argue in favor of; also one who does	alter	to change
assess	to judge the size or state of	assume	to take as true without proof
attribute	to name as the cause of	benefit	an advantage gained
capacity	the most something can hold or do	category	a class of things sharing a feature
circumstance	the conditions around an event	coherent	logically connected and easy to follow
coincide	to happen at the same time	commence	to begin
component	one part of a whole	comprehensive	covering everything needed
concurrent	happening at the same time	confirm	to establish as true
considerable	large in amount	constitute	to make up
criteria	the standards a judgment is made against	crucial	decisive; hard to do without
cumulative	building up by addition	decline	to fall
demonstrate	to show by evidence or by doing	derive	to obtain from a source
detect	to find something not obvious	determine	to settle, or to find out with certainty
deviate	to depart from a standard	diminish	to grow smaller
discrete	separate, not continuous	distribute	to spread among places or people
diverse	varied in kind	duration	how long something lasts
emphasize	to give special weight to	enhance	to raise in quality or degree
ensure	to make certain	equivalent	equal in value or meaning
establish	to set up, or to prove	evaluate	to judge against criteria
evident	clear from what can be seen	exclude	to leave out
explicit	stated outright, with nothing left to infer	factor	one thing that contributes to a result
fluctuate	to rise and fall repeatedly	fundamental	forming the base of the rest
hypothesis	a proposed explanation to be tested	identify	to name or recognize
illustrate	to make clear by example	impact	a strong effect
implement	to put into effect	indicate	to point to
inevitable	unavoidable	initial	first, at the start
integrate	to combine into one whole	interpret	to explain the meaning of
intervene	to step in	justify	to show to be reasonable
maintain	to keep in the same state	mechanism	the process by which something works
modify	to change in part	obtain	to get
occur	to happen	outcome	the result at the end
perceive	to notice or understand	persist	to continue despite opposition
potential	possible but not yet actual	precede	to come before

B. Health-care terms (45)

A passage about a patient may use these without stopping to define them.

Term	Means	Term	Means
abduction	movement away from the body's midline	adherence	the extent to which a patient follows a plan
analgesic	a medicine that relieves pain	anemia	too few red cells, or too little hemoglobin
anterior	toward the front of the body	aseptic	free of disease-causing organisms
auscultate	to listen to body sounds with a stethoscope	bilateral	on both sides
bradycardia	a slow heart rate	carcinoma	a cancer arising in a tissue's cells
cognition	thinking, memory and awareness	contraindication	a reason not to give a treatment
defecate	to pass stool	dehydration	a body short of water
dementia	a decline in memory and reasoning	diagnosis	the name given to a condition after assessment
diastolic	the pressure while the heart refills	diuretic	a medicine that increases urine output
dyspnea	difficult or short breathing	edema	swelling from fluid in tissue
etiology	the cause of a condition	exudate	fluid leaking from tissue, often with cells and protein
gestation	pregnancy, from conception to birth	glucose	the sugar cells burn for energy
hemorrhage	heavy bleeding	hypertension	high blood pressure
hypotension	low blood pressure	hypoxia	too little oxygen reaching tissue
incision	a surgical cut	inflammation	the response to injury: heat, swelling, pain, redness
infusion	fluid given slowly into a vein	ischemia	tissue starved of blood flow
lateral	toward the side	lesion	an area of damaged tissue
metabolism	the chemical work a body does to stay alive	occlude	to block
palliate	to relieve without curing	palpate	to examine by touch
parenteral	by a route other than the digestive tract	posterior	toward the back of the body
prognosis	the likely course of a condition	prophylaxis	action taken to prevent disease
sepsis	a life-threatening response to infection	systolic	the pressure while the heart contracts
tachycardia	a fast heart rate

C. Science and math words (35)

These appear in a science or math passage as vocabulary. The idea behind each is developed on the subject's own guide.

Word	Means	Word	Means
absorption	taking a substance in across a surface	acid	a substance that gives up hydrogen ions
alkaline	basic; able to accept hydrogen ions	catalyst	a substance that speeds a reaction without being used up
compound	two or more elements joined chemically	concentration	how much of a substance is in a given volume
density	mass per unit of volume	diffusion	movement of particles from crowded to empty
dilution	adding solvent to lower a concentration	electron	a negatively charged particle of an atom
equilibrium	the state where forward and reverse change balance	filtrate	fluid that has passed through a filter
gradient	a difference across a distance that drives movement	ion	an atom or molecule carrying a charge
kilocalorie	the energy that raises one kilogram of water one degree	molarity	moles of solute per liter of solution
molecule	two or more atoms bonded together	neutral	neither acidic nor basic
osmosis	water crossing a membrane toward more solute	oxidation	loss of electrons
permeability	how easily a substance crosses a membrane	pH	the scale of hydrogen-ion concentration
precision	how close repeated measurements are to each other	product	a substance formed by a reaction
rate	how much changes per unit of time	ratio	the relative size of two quantities
reactant	a substance consumed by a reaction	reduction	gain of electrons
saturation	the point where no more solute will dissolve	solute	the substance that is dissolved
solvent	the substance doing the dissolving	substrate	the molecule an enzyme acts on
temperature	a measure of average particle energy	variance	how far values spread from their mean
volume	the space a substance occupies

How to drill 150 words without wasting the week

Three passes, a week apart, and each pass from the harder side of the card:

Cover the meaning, read the word, say the meaning. This is recognition, and it is the pass that makes the harder one possible.
Cover the word, read the meaning, say the word. This is recall, and it is the pass that proves the first one worked. A word you can only recognize is a word you will miss when the question uses a different form of it.
Say each word in a sentence about a patient. Two words a sentence is enough. The sentence is where a definition turns into vocabulary, and it is the shape the word arrives in on the page — inside a passage, doing a job.

Ten words at a sitting, fifteen sittings, five days. The list is alphabetized so a sitting has a start and an end rather than a mood.

What this list is not

It is not the exam's word list, because the exam does not publish one. It is not a substitute for the word parts — a passage can hand you a term nobody has listed, and taking it apart is the only method that still works. And it is not a dictionary: each gloss gives the one sense a health-care passage uses, which is why decline is glossed as a fall and not as a refusal, though both are correct English.

If a word on this list is still not clear, the glossary has longer entries for the terms this course teaches in depth, and each subject guide develops its own vocabulary in context — reading comprehension, measurement and conversion, grammar, biology.

Sources. Elsevier's own HESI A2 page names vocabulary among the areas the exam covers and states that it includes practice questions for all sections of the Admission Assessment Exam; it publishes no word list, count or weighting, and nothing here claims to mirror one. The medical word parts the guide teaches follow MedlinePlus (US National Library of Medicine) consumer guidance on understanding medical words, US federal government material not subject to copyright in the United States. Every gloss and sentence on this page was written for this course. 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.

HESI A2 vocabulary list: 150 words with meanings