Stable angina usually reflects fixed coronary narrowing that limits blood flow during increased demand. Unstable angina reflects a changing coronary process, often plaque disruption and thrombosis, causing ischemia without detectable myocardial necrosis. NSTEMI and STEMI involve myocardial injury or infarction. Angina can also arise from vasospasm, microvascular dysfunction, anemia, tachyarrhythmia, hypoxia, severe hypertension, or other demand states. For NP certification preparation (United States), items rarely announce the topic in the first sentence. Anchor to objective data, trajectory, and the safest next step for the role named in the stem before distractors compete. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and end organs, neuro baseline, likely infection sources, and devices that can fail quietly. When two answers feel partly right, pick the one that reduces imminent harm and matches orders for the role you were given. Train yourself to...