USMLE Step 3 Exam Practice Questions
And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
Pdf
1. A 67-year-old man with hypertension and diabetes presents with
sudden onset right-sided weakness and aphasia lasting 90 minutes,
now resolving. Blood pressure is 178/96 mmHg. CT head is normal.
What is the next best step in management?
A. Start aspirin immediately
B. Administer IV alteplase
C. Begin warfarin therapy
D. No treatment required
B
This presentation is consistent with an acute ischemic stroke within the
thrombolytic window, and IV alteplase is indicated if no contraindications
exist despite elevated blood pressure below the treatment exclusion
threshold after controlled reduction.
2. A 58-year-old woman presents with crushing chest pain radiating to
the left arm. ECG shows ST elevation in II, III, aVF. What is the most
likely affected artery?
A. LAD
, B. Right coronary artery
C. Left circumflex artery
D. Left main coronary artery
B
Inferior wall myocardial infarction with ST elevation in II, III, and aVF most
commonly results from occlusion of the right coronary artery.
3. A 45-year-old man has progressive dyspnea and bilateral crackles.
Echocardiogram shows EF 25%. Which medication improves mortality?
A. Furosemide
B. Digoxin
C. Metoprolol succinate
D. Nifedipine
C
Beta-blockers such as metoprolol succinate reduce mortality in systolic
heart failure by decreasing sympathetic overactivity and remodeling.
4. A 30-year-old woman presents with exophthalmos, heat intolerance,
and weight loss. TSH is low, T3/T4 elevated. What is the mechanism?
A. Thyroid destruction
B. TSH receptor stimulation by antibodies
C. Pituitary adenoma
D. Iodine deficiency
B
Graves disease is caused by TSH receptor–stimulating autoantibodies
leading to increased thyroid hormone production.
5. A 72-year-old man has painless hematuria. He is a smoker. Most likely
diagnosis?
A. Renal cell carcinoma
B. Bladder cancer
, C. UTI
D. Kidney stones
B
Painless gross hematuria in an older smoker is most strongly associated
with transitional cell carcinoma of the bladder.
6. A newborn has cyanosis that does not improve with oxygen. ECG
shows right ventricular hypertrophy. Most likely diagnosis?
A. Tetralogy of Fallot
B. Transposition of great vessels
C. Truncus arteriosus
D. PDA
B
Transposition of the great vessels causes severe cyanosis unresponsive to
oxygen due to parallel circulation.
7. A patient develops fever, rigidity, and altered mental status after
starting haloperidol. Diagnosis?
A. Serotonin syndrome
B. Neuroleptic malignant syndrome
C. Malignant hyperthermia
D. Meningitis
B
Neuroleptic malignant syndrome is caused by dopamine blockade and
presents with hyperthermia, rigidity, and autonomic instability.
8. A 25-year-old woman has dysuria and frequency. Urinalysis shows
nitrites and leukocyte esterase. Most likely organism?
A. Staphylococcus saprophyticus
B. Escherichia coli
, C. Candida albicans
D. Neisseria gonorrhoeae
B
E. coli is the most common cause of uncomplicated urinary tract infections
and produces nitrites on urinalysis.
9. A 60-year-old man with cirrhosis presents with ascites. SAAG is >1.1.
Mechanism?
A. Increased oncotic pressure
B. Portal hypertension
C. Nephrotic syndrome
D. Infection
B
High SAAG ascites indicates portal hypertension as the cause of fluid
accumulation in cirrhosis.
10. A child presents with a “slapped cheek” rash and joint pain.
Cause?
A. Parvovirus B19
B. Measles virus
C. Rubella virus
D. EBV
A
Parvovirus B19 causes erythema infectiosum characterized by slapped
cheek rash and arthralgia.
11. A patient has severe epigastric pain relieved by eating. Likely
diagnosis?
A. Gastric ulcer
B. Duodenal ulcer
And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A 67-year-old man with hypertension and diabetes presents with
sudden onset right-sided weakness and aphasia lasting 90 minutes,
now resolving. Blood pressure is 178/96 mmHg. CT head is normal.
What is the next best step in management?
A. Start aspirin immediately
B. Administer IV alteplase
C. Begin warfarin therapy
D. No treatment required
B
This presentation is consistent with an acute ischemic stroke within the
thrombolytic window, and IV alteplase is indicated if no contraindications
exist despite elevated blood pressure below the treatment exclusion
threshold after controlled reduction.
2. A 58-year-old woman presents with crushing chest pain radiating to
the left arm. ECG shows ST elevation in II, III, aVF. What is the most
likely affected artery?
A. LAD
, B. Right coronary artery
C. Left circumflex artery
D. Left main coronary artery
B
Inferior wall myocardial infarction with ST elevation in II, III, and aVF most
commonly results from occlusion of the right coronary artery.
3. A 45-year-old man has progressive dyspnea and bilateral crackles.
Echocardiogram shows EF 25%. Which medication improves mortality?
A. Furosemide
B. Digoxin
C. Metoprolol succinate
D. Nifedipine
C
Beta-blockers such as metoprolol succinate reduce mortality in systolic
heart failure by decreasing sympathetic overactivity and remodeling.
4. A 30-year-old woman presents with exophthalmos, heat intolerance,
and weight loss. TSH is low, T3/T4 elevated. What is the mechanism?
A. Thyroid destruction
B. TSH receptor stimulation by antibodies
C. Pituitary adenoma
D. Iodine deficiency
B
Graves disease is caused by TSH receptor–stimulating autoantibodies
leading to increased thyroid hormone production.
5. A 72-year-old man has painless hematuria. He is a smoker. Most likely
diagnosis?
A. Renal cell carcinoma
B. Bladder cancer
, C. UTI
D. Kidney stones
B
Painless gross hematuria in an older smoker is most strongly associated
with transitional cell carcinoma of the bladder.
6. A newborn has cyanosis that does not improve with oxygen. ECG
shows right ventricular hypertrophy. Most likely diagnosis?
A. Tetralogy of Fallot
B. Transposition of great vessels
C. Truncus arteriosus
D. PDA
B
Transposition of the great vessels causes severe cyanosis unresponsive to
oxygen due to parallel circulation.
7. A patient develops fever, rigidity, and altered mental status after
starting haloperidol. Diagnosis?
A. Serotonin syndrome
B. Neuroleptic malignant syndrome
C. Malignant hyperthermia
D. Meningitis
B
Neuroleptic malignant syndrome is caused by dopamine blockade and
presents with hyperthermia, rigidity, and autonomic instability.
8. A 25-year-old woman has dysuria and frequency. Urinalysis shows
nitrites and leukocyte esterase. Most likely organism?
A. Staphylococcus saprophyticus
B. Escherichia coli
, C. Candida albicans
D. Neisseria gonorrhoeae
B
E. coli is the most common cause of uncomplicated urinary tract infections
and produces nitrites on urinalysis.
9. A 60-year-old man with cirrhosis presents with ascites. SAAG is >1.1.
Mechanism?
A. Increased oncotic pressure
B. Portal hypertension
C. Nephrotic syndrome
D. Infection
B
High SAAG ascites indicates portal hypertension as the cause of fluid
accumulation in cirrhosis.
10. A child presents with a “slapped cheek” rash and joint pain.
Cause?
A. Parvovirus B19
B. Measles virus
C. Rubella virus
D. EBV
A
Parvovirus B19 causes erythema infectiosum characterized by slapped
cheek rash and arthralgia.
11. A patient has severe epigastric pain relieved by eating. Likely
diagnosis?
A. Gastric ulcer
B. Duodenal ulcer
