United States Medical Licensing Examination
(USMLE) practice test with 70 questions from
actual past exam 100% correct answers and
rationale
USMLE Practice Test: 70 Questions
Question 1 (Step 1: Pathology)A 25-year-old male presents with fatigue and pallor. Labs show
hemoglobin 8 g/dL, MCV 70 fL, and peripheral smear with hypochromic microcytic red cells.
What is the most likely diagnosis?
A. Sickle cell anemia
B. Iron deficiency anemia
C. Thalassemia major
D. Anemia of chronic disease Correct Answer: B
Rationale: Hypochromic microcytic anemia with low hemoglobin and MCV suggests iron
deficiency anemia, common in young adults due to poor diet or blood loss. Sickle cell anemia
presents with normocytic anemia, thalassemia major is more severe, and anemia of chronic
disease is normocytic or slightly microcytic.
Question 2 (Step 1: Pharmacology)A 55-year-old female with hypertension is prescribed
lisinopril. Which side effect is most commonly associated with this medication?
A. Hyperkalemia
B. Hypoglycemia
C. Bradycardia
D. Hyponatremia Correct Answer: A
Rationale: Lisinopril, an ACE inhibitor, reduces aldosterone, leading to potassium retention and
potential hyperkalemia.
Question 3 (Step 2 CK: Internal Medicine)A 60-year-old male presents with chest pain radiating
to the left arm, diaphoresis, and nausea. ECG shows ST elevation in leads V1–V4. What is the
immediate treatment?
A. Aspirin and heparin
B. Metoprolol and atorvastatin
C. Percutaneous coronary intervention (PCI)
D. Nitroglycerin only Correct Answer: C
Rationale: ST-elevation myocardial infarction (STEMI) requires urgent PCI within 90 minutes if
available. Aspirin and heparin are adjuncts, but PCI is the primary intervention.
Question 4 (Step 3: Patient Management)A 45-year-old female with type 2 diabetes has an
HbA1c of 8.5%. She is on metformin 1000 mg twice daily. What is the next step in
management?
A. Continue metformin alone
B. Add insulin glargine
, C. Add sulfonylurea
D. Discontinue metformin Correct Answer: C
Rationale: For HbA1c >7% despite metformin, adding a sulfonylurea (e.g., glipizide) is a
common next step to improve glycemic control. Insulin is considered if oral agents fail.
Question 5 (Step 1: Microbiology)A 30-year-old male presents with fever, cough, and weight
loss. Chest X-ray shows cavitary lesions in the upper lobes. Acid-fast bacilli are found in
sputum. What is the most likely organism?
A. Streptococcus pneumoniae
B. Mycobacterium tuberculosis
C. Staphylococcus aureus
D. Klebsiella pneumoniae Correct Answer: B
Rationale: Cavitary lesions and acid-fast bacilli in sputum are characteristic of pulmonary
tuberculosis caused by Mycobacterium tuberculosis.
Question 6 (Step 2 CK: Pediatrics)A 2-year-old child presents with fever, rash, and
conjunctivitis. Physical exam reveals a “strawberry tongue.” What is the most likely diagnosis?
A. Measles
B. Scarlet fever
C. Kawasaki disease
D. Roseola Correct Answer: C
Rationale: Fever, rash, conjunctivitis, and strawberry tongue are classic features of Kawasaki
disease, a vasculitis in children.
Question 7 (Step 3: Ethics)A 70-year-old male with terminal lung cancer refuses chemotherapy
despite understanding the prognosis. What should the physician do?
A. Administer chemotherapy
B. Respect the patient’s decision
C. Seek a court order
D. Convince the patient to reconsider Correct Answer: B
Rationale: Patient autonomy must be respected if the patient is competent and understands the
consequences, per medical ethics principles.
Question 8 (Step 1: Physiology)Which hormone is primarily responsible for increasing blood
glucose during fasting?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine Correct Answer: B
Rationale: Glucagon stimulates glycogenolysis and gluconeogenesis in the liver, increasing
blood glucose during fasting.
Question 9 (Step 2 CK: Surgery)A 50-year-old male presents with right lower quadrant pain,
fever, and leukocytosis. CT shows a thickened appendix with fat stranding. What is the
treatment?
A. Antibiotics only
(USMLE) practice test with 70 questions from
actual past exam 100% correct answers and
rationale
USMLE Practice Test: 70 Questions
Question 1 (Step 1: Pathology)A 25-year-old male presents with fatigue and pallor. Labs show
hemoglobin 8 g/dL, MCV 70 fL, and peripheral smear with hypochromic microcytic red cells.
What is the most likely diagnosis?
A. Sickle cell anemia
B. Iron deficiency anemia
C. Thalassemia major
D. Anemia of chronic disease Correct Answer: B
Rationale: Hypochromic microcytic anemia with low hemoglobin and MCV suggests iron
deficiency anemia, common in young adults due to poor diet or blood loss. Sickle cell anemia
presents with normocytic anemia, thalassemia major is more severe, and anemia of chronic
disease is normocytic or slightly microcytic.
Question 2 (Step 1: Pharmacology)A 55-year-old female with hypertension is prescribed
lisinopril. Which side effect is most commonly associated with this medication?
A. Hyperkalemia
B. Hypoglycemia
C. Bradycardia
D. Hyponatremia Correct Answer: A
Rationale: Lisinopril, an ACE inhibitor, reduces aldosterone, leading to potassium retention and
potential hyperkalemia.
Question 3 (Step 2 CK: Internal Medicine)A 60-year-old male presents with chest pain radiating
to the left arm, diaphoresis, and nausea. ECG shows ST elevation in leads V1–V4. What is the
immediate treatment?
A. Aspirin and heparin
B. Metoprolol and atorvastatin
C. Percutaneous coronary intervention (PCI)
D. Nitroglycerin only Correct Answer: C
Rationale: ST-elevation myocardial infarction (STEMI) requires urgent PCI within 90 minutes if
available. Aspirin and heparin are adjuncts, but PCI is the primary intervention.
Question 4 (Step 3: Patient Management)A 45-year-old female with type 2 diabetes has an
HbA1c of 8.5%. She is on metformin 1000 mg twice daily. What is the next step in
management?
A. Continue metformin alone
B. Add insulin glargine
, C. Add sulfonylurea
D. Discontinue metformin Correct Answer: C
Rationale: For HbA1c >7% despite metformin, adding a sulfonylurea (e.g., glipizide) is a
common next step to improve glycemic control. Insulin is considered if oral agents fail.
Question 5 (Step 1: Microbiology)A 30-year-old male presents with fever, cough, and weight
loss. Chest X-ray shows cavitary lesions in the upper lobes. Acid-fast bacilli are found in
sputum. What is the most likely organism?
A. Streptococcus pneumoniae
B. Mycobacterium tuberculosis
C. Staphylococcus aureus
D. Klebsiella pneumoniae Correct Answer: B
Rationale: Cavitary lesions and acid-fast bacilli in sputum are characteristic of pulmonary
tuberculosis caused by Mycobacterium tuberculosis.
Question 6 (Step 2 CK: Pediatrics)A 2-year-old child presents with fever, rash, and
conjunctivitis. Physical exam reveals a “strawberry tongue.” What is the most likely diagnosis?
A. Measles
B. Scarlet fever
C. Kawasaki disease
D. Roseola Correct Answer: C
Rationale: Fever, rash, conjunctivitis, and strawberry tongue are classic features of Kawasaki
disease, a vasculitis in children.
Question 7 (Step 3: Ethics)A 70-year-old male with terminal lung cancer refuses chemotherapy
despite understanding the prognosis. What should the physician do?
A. Administer chemotherapy
B. Respect the patient’s decision
C. Seek a court order
D. Convince the patient to reconsider Correct Answer: B
Rationale: Patient autonomy must be respected if the patient is competent and understands the
consequences, per medical ethics principles.
Question 8 (Step 1: Physiology)Which hormone is primarily responsible for increasing blood
glucose during fasting?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine Correct Answer: B
Rationale: Glucagon stimulates glycogenolysis and gluconeogenesis in the liver, increasing
blood glucose during fasting.
Question 9 (Step 2 CK: Surgery)A 50-year-old male presents with right lower quadrant pain,
fever, and leukocytosis. CT shows a thickened appendix with fat stranding. What is the
treatment?
A. Antibiotics only
