HESI A2 Study Guide

This 8-week HESI A2 study guide is structured around the exam's actual section weights. Anatomy & Physiology comes first because it carries the largest science question load at most nursing programs, and because it takes the longest to learn. Students who build an A&P foundation in the first two weeks consistently report stronger section scores across the rest of the exam.

“The most common HESI study mistake is underestimating A&P and overestimating Math. Reverse that assumption and your score usually goes up.”

— StudyBuddy Doctoral Faculty

The 8-week HESI A2 study plan

1Baseline + Anatomy & Physiology I
Take a full-length HESI A2 diagnostic to set your baseline across all scored sections. Then begin A&P: cardiovascular system (heart chambers, cardiac cycle, blood flow, blood pressure regulation), respiratory system (gas exchange, ventilation mechanics, respiratory control), and renal system (nephron structure, filtration, fluid and electrolyte balance). A&P is commonly weighted 25–30 questions on the HESI — it is the single highest-return area to master first.
2A&P II + Biology
Continue A&P: nervous system (action potentials, synaptic transmission, central vs. peripheral), endocrine system (hormones, feedback loops, pancreas and thyroid), immune system (innate vs. adaptive immunity, antibody types). Move to Biology: cell structure (organelles and their functions), cell transport (active, passive, osmosis), cell division (mitosis vs. meiosis), genetics (Mendelian patterns, Punnett squares, DNA and RNA).
3Chemistry
Atomic structure (protons, neutrons, electrons, isotopes), the periodic table (trends in reactivity and electronegativity), chemical bonding (ionic, covalent, polar vs. nonpolar), chemical reactions (balancing equations, types of reactions), solutions and concentrations (molarity, dilution), acids and bases (pH, buffers). HESI Chemistry often catches students who have not taken a chemistry course in the past 3 years.
4Mathematics
Arithmetic (fractions, decimals, percentages, ratios, proportions), basic algebra (solving for x, word problems), measurement conversions (metric system, household units, medical dosage conversions), statistics basics (mean, median, mode), and geometry basics. A calculator is not permitted on HESI Math — practice working problems by hand. Drill 40+ timed questions per day this week.
5Reading Comprehension + Vocabulary
Reading: identify main idea, distinguish supporting details from filler, recognize author tone and purpose, make inferences grounded strictly in the passage. Vocabulary: medical terminology with prefixes (pre-, post-, hyper-, hypo-), roots (cardi-, pulmon-, nephr-, hepato-), and suffixes (-itis, -ectomy, -ology). Review 50 medical terms per day. HESI Vocabulary rewards rote drilling — flashcards work well here.
6Grammar + Optional sections
Grammar: parts of speech, subject-verb agreement, pronoun-antecedent agreement, commonly confused words (affect vs. effect, fewer vs. less), punctuation rules (commas, semicolons, apostrophes), sentence structure. If your program requires Physics, cover the basics this week: forces (Newton’s laws), motion and kinematics, energy conservation, simple machines. Verify with your admissions office which sections your program scores.
7Full practice exam + weak-area targeting
Take a full-length timed HESI A2 practice exam on day 1 under exam conditions. Review only the wrong answers, not the entire exam. Spend days 2–6 drilling your two lowest-scoring sections with 50+ targeted questions per day. Use your StudyBuddy AI tutor to explain the reasoning you are missing, not just the correct answers.
8Final exam + test-day readiness
Take a final full-length timed practice exam in the first half of week 8. Compare your section scores to your week 1 baseline. Review errors only. Stop all new content 36 hours before your exam. Sleep, hydrate, confirm your testing center location and required ID. Do not study the morning of the exam — trust the preparation.

Study guide questions

How long should I study for the HESI A2?
Most students need 6–10 weeks at 10–15 hours per week. Students with recent college-level Biology, Chemistry, and A&P may need 6 weeks. Students who have not taken science in several years should plan for 10+ weeks. Your strongest leverage point is A&P — carving out extra time here pays back more than any other section.
What should I study first for the HESI A2?
Anatomy & Physiology first, then Biology and Chemistry. A&P has the highest question weight on the HESI of any single science section at most programs, and it is the section where cramming works worst. Students who master A&P in weeks 1–2 typically achieve strong section scores across the rest of the exam.
How many practice tests should I take for the HESI A2?
At minimum, take 2 full-length timed practice exams: one in week 1 to establish your baseline and one in week 7 or 8 to simulate test day. More is better if your schedule allows. Practice exams should always be timed, taken without notes, and followed by focused review — untimed practice does not build the pacing HESI requires.
Is the HESI A2 harder than the TEAS 7?
They test different things. The HESI has separate sections for Biology, Chemistry, A&P, and sometimes Physics — a broader science surface area. The TEAS combines science into one section. The HESI is longer (~5 hours vs. ~3.5 hours for the TEAS). Some students prefer the HESI because weak areas do not drag down a single composite score — each section is reported independently.
Which HESI A2 sections does my school require?
Each nursing program selects which HESI sections to score. Nearly all require Math, Reading, Grammar, Vocabulary, Biology, and A&P. Chemistry is required by most BSN programs. Physics is required by a small number of programs. Contact your admissions office and confirm the exact sections and minimum scores — do not rely on published cutoffs alone.

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Section-by-section strategy, score targets, and a study schedule. Faculty-developed.