USMLE STEP 3 – PRACTICE QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
*Core Domains*
*Internal Medicine*
*Pediatrics*
*Obstetrics and Gynecology*
*Surgery*
*Psychiatry*
*Ethics and Medical Jurisprudence*
*Preventive Medicine and Biostatistics*
*Emergency Medicine*
*Introduction*
The purpose of this examination is to evaluate a physician’s ability to apply medical
knowledge and understanding of biomedical and clinical science essential for the
unsupervised practice of medicine. This assessment focuses on the management of
patient care in various settings, emphasizing clinical decision-making, health
maintenance, and disease prevention. The questions utilize a mix of clinical vignettes
and scenario-based structures to test real-world application. Candidates are expected
,to demonstrate proficiency in diagnostic reasoning, therapeutic management, and
professional ethics. This comprehensive review ensures a balanced representation of
clinical challenges encountered in generalist medical practice, requiring critical
thinking and evidence-based solutions.
SECTION ONE: QUESTIONS 1–100
1. A 64-year-old male presents with a 4-hour history of severe substernal chest
pain radiating to his left jaw. He has a history of hypertension and tobacco use.
ECG shows ST-segment elevation in leads II, III, and aVF. Which of the
following is the most appropriate next step in management?
A. Immediate administration of oral beta-blockers
B. Emergent cardiac catheterization for primary PCI
C. Administration of intravenous corticosteroids
D. Observation in the telemetry unit for 24 hours
🟢 Correct answer B. Emergent cardiac catheterization for primary PCI
🔴 RATIONALE: The patient is presenting with an inferior ST-elevation myocardial
infarction (STEMI). Reperfusion therapy via Primary Percutaneous Coronary
,Intervention (PCI) is the gold standard when available within 90 minutes of medical
contact to reduce mortality and infarct size.
2. A 32-year-old female at 28 weeks gestation presents with sudden onset of
headache and blurry vision. Her blood pressure is 165/110 mmHg. Urinalysis
shows 3+ protein. What is the most appropriate medication to prevent seizures
in this patient?
A. Phenytoin
B. Diazepam
🟢 Correct answer C. Magnesium sulfate
D. Valproate
🔴 RATIONALE: This patient meets the criteria for preeclampsia with severe
features. Magnesium sulfate is the treatment of choice for seizure prophylaxis in
preeclampsia and management of eclampsia, as it is more effective than standard
anticonvulsants.
3. A 45-year-old man with a history of alcohol use disorder is brought to the
emergency department after being found down. He is confused and has
horizontal nystagmus and an ataxic gait. Which of the following should be
administered first?
, 🟢 Correct answer A. Intravenous thiamine
B. Intravenous dextrose 50%
C. Intravenous haloperidol
D. Oral chlordiazepoxide
🔴 RATIONALE: The triad of confusion, ataxia, and ophthalmoplegia/nystagmus is
classic for Wernicke encephalopathy. Thiamine must be administered before or
concurrently with glucose to avoid worsening the condition, as glucose can deplete
remaining thiamine stores.
4. A 72-year-old woman is admitted for a hip fracture. On postoperative day 2, she
becomes acutely confused and starts seeing "insects" on the wall. She is
oriented only to person. What is the most likely diagnosis?
A. Alzheimer's dementia
B. Schizophrenia
C. Vascular dementia
🟢 Correct answer D. Delirium
🔴 RATIONALE: Delirium is characterized by an acute, fluctuating change in mental
status and sensorium (e.g., visual hallucinations). It is common in elderly
ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
*Core Domains*
*Internal Medicine*
*Pediatrics*
*Obstetrics and Gynecology*
*Surgery*
*Psychiatry*
*Ethics and Medical Jurisprudence*
*Preventive Medicine and Biostatistics*
*Emergency Medicine*
*Introduction*
The purpose of this examination is to evaluate a physician’s ability to apply medical
knowledge and understanding of biomedical and clinical science essential for the
unsupervised practice of medicine. This assessment focuses on the management of
patient care in various settings, emphasizing clinical decision-making, health
maintenance, and disease prevention. The questions utilize a mix of clinical vignettes
and scenario-based structures to test real-world application. Candidates are expected
,to demonstrate proficiency in diagnostic reasoning, therapeutic management, and
professional ethics. This comprehensive review ensures a balanced representation of
clinical challenges encountered in generalist medical practice, requiring critical
thinking and evidence-based solutions.
SECTION ONE: QUESTIONS 1–100
1. A 64-year-old male presents with a 4-hour history of severe substernal chest
pain radiating to his left jaw. He has a history of hypertension and tobacco use.
ECG shows ST-segment elevation in leads II, III, and aVF. Which of the
following is the most appropriate next step in management?
A. Immediate administration of oral beta-blockers
B. Emergent cardiac catheterization for primary PCI
C. Administration of intravenous corticosteroids
D. Observation in the telemetry unit for 24 hours
🟢 Correct answer B. Emergent cardiac catheterization for primary PCI
🔴 RATIONALE: The patient is presenting with an inferior ST-elevation myocardial
infarction (STEMI). Reperfusion therapy via Primary Percutaneous Coronary
,Intervention (PCI) is the gold standard when available within 90 minutes of medical
contact to reduce mortality and infarct size.
2. A 32-year-old female at 28 weeks gestation presents with sudden onset of
headache and blurry vision. Her blood pressure is 165/110 mmHg. Urinalysis
shows 3+ protein. What is the most appropriate medication to prevent seizures
in this patient?
A. Phenytoin
B. Diazepam
🟢 Correct answer C. Magnesium sulfate
D. Valproate
🔴 RATIONALE: This patient meets the criteria for preeclampsia with severe
features. Magnesium sulfate is the treatment of choice for seizure prophylaxis in
preeclampsia and management of eclampsia, as it is more effective than standard
anticonvulsants.
3. A 45-year-old man with a history of alcohol use disorder is brought to the
emergency department after being found down. He is confused and has
horizontal nystagmus and an ataxic gait. Which of the following should be
administered first?
, 🟢 Correct answer A. Intravenous thiamine
B. Intravenous dextrose 50%
C. Intravenous haloperidol
D. Oral chlordiazepoxide
🔴 RATIONALE: The triad of confusion, ataxia, and ophthalmoplegia/nystagmus is
classic for Wernicke encephalopathy. Thiamine must be administered before or
concurrently with glucose to avoid worsening the condition, as glucose can deplete
remaining thiamine stores.
4. A 72-year-old woman is admitted for a hip fracture. On postoperative day 2, she
becomes acutely confused and starts seeing "insects" on the wall. She is
oriented only to person. What is the most likely diagnosis?
A. Alzheimer's dementia
B. Schizophrenia
C. Vascular dementia
🟢 Correct answer D. Delirium
🔴 RATIONALE: Delirium is characterized by an acute, fluctuating change in mental
status and sensorium (e.g., visual hallucinations). It is common in elderly
