NSG 550 Diagnostic Reasoning | Practice Test 50
Questions With Answers & Rationales | 2025-2026
Updates
1.
A 45-year-old woman presents with fatigue, weight gain, dry skin, and cold intolerance. On exam you note
delayed deep tendon reflexes. Which initial test best confirms your suspected diagnosis?
A. Serum cortisol
B. Serum TSH
C. Fasting glucose
D. ANA
Answer: B
Rationale: The presentation suggests hypothyroidism. TSH is the most sensitive initial test to confirm it.
2.
A 62-year-old male presents with new onset exertional chest pain. Which feature most strongly supports an
ischemic etiology?
A. Pain reproducible with palpation
B. Pain worsens with meals
C. Pain relieved by rest
D. Pain constant for several hours
Answer: C
Rationale: Anginal pain is typically exertional and relieved by rest or nitroglycerin. Reproducible pain suggests
musculoskeletal origin.
3.
You’re evaluating a 3-year-old with fever, inspiratory stridor, and drooling. What is the most likely diagnosis?
A. Croup
,B. Epiglottitis
C. Foreign body aspiration
D. Bronchiolitis
Answer: B
Rationale: Acute onset of fever, stridor, and drooling suggests epiglottitis — a medical emergency.
4.
During diagnostic reasoning, which step occurs first?
A. Generate differential diagnoses
B. Identify chief complaint
C. Select diagnostic tests
D. Initiate treatment
Answer: B
Rationale: The diagnostic process begins with identifying the patient’s chief complaint and history of present
illness before generating differentials.
5.
A patient with COPD presents with worsening dyspnea. You suspect pneumonia. Which diagnostic test has the
highest yield to confirm your suspicion?
A. ABG
B. Chest X-ray
C. Spirometry
D. Peak flow
Answer: B
Rationale: Chest radiograph is the primary imaging to confirm pneumonia.
6.
A 25-year-old male presents with dysuria and urethral discharge. Which finding most strongly supports
gonococcal infection?
, A. Scrotal mass
B. Purulent discharge
C. Painless ulcer
D. Vesicular rash
Answer: B
Rationale: Purulent urethral discharge and dysuria are classic for gonorrhea; painless ulcer = syphilis, vesicles
= HSV.
7.
In diagnostic reasoning, “heuristics” refer to:
A. Stepwise, evidence-based algorithms
B. Mental shortcuts used to make quick decisions
C. Random guessing
D. Laboratory error
Answer: B
Rationale: Heuristics are cognitive shortcuts; they speed decisions but can introduce bias.
8.
A 70-year-old diabetic presents with unilateral headache, jaw claudication, and vision changes. Which lab
should you order immediately?
A. ESR
B. Fasting glucose
C. PSA
D. BNP
Answer: A
Rationale: Symptoms suggest giant cell arteritis; elevated ESR supports diagnosis, and prompt treatment is
needed to prevent blindness.
9.
Questions With Answers & Rationales | 2025-2026
Updates
1.
A 45-year-old woman presents with fatigue, weight gain, dry skin, and cold intolerance. On exam you note
delayed deep tendon reflexes. Which initial test best confirms your suspected diagnosis?
A. Serum cortisol
B. Serum TSH
C. Fasting glucose
D. ANA
Answer: B
Rationale: The presentation suggests hypothyroidism. TSH is the most sensitive initial test to confirm it.
2.
A 62-year-old male presents with new onset exertional chest pain. Which feature most strongly supports an
ischemic etiology?
A. Pain reproducible with palpation
B. Pain worsens with meals
C. Pain relieved by rest
D. Pain constant for several hours
Answer: C
Rationale: Anginal pain is typically exertional and relieved by rest or nitroglycerin. Reproducible pain suggests
musculoskeletal origin.
3.
You’re evaluating a 3-year-old with fever, inspiratory stridor, and drooling. What is the most likely diagnosis?
A. Croup
,B. Epiglottitis
C. Foreign body aspiration
D. Bronchiolitis
Answer: B
Rationale: Acute onset of fever, stridor, and drooling suggests epiglottitis — a medical emergency.
4.
During diagnostic reasoning, which step occurs first?
A. Generate differential diagnoses
B. Identify chief complaint
C. Select diagnostic tests
D. Initiate treatment
Answer: B
Rationale: The diagnostic process begins with identifying the patient’s chief complaint and history of present
illness before generating differentials.
5.
A patient with COPD presents with worsening dyspnea. You suspect pneumonia. Which diagnostic test has the
highest yield to confirm your suspicion?
A. ABG
B. Chest X-ray
C. Spirometry
D. Peak flow
Answer: B
Rationale: Chest radiograph is the primary imaging to confirm pneumonia.
6.
A 25-year-old male presents with dysuria and urethral discharge. Which finding most strongly supports
gonococcal infection?
, A. Scrotal mass
B. Purulent discharge
C. Painless ulcer
D. Vesicular rash
Answer: B
Rationale: Purulent urethral discharge and dysuria are classic for gonorrhea; painless ulcer = syphilis, vesicles
= HSV.
7.
In diagnostic reasoning, “heuristics” refer to:
A. Stepwise, evidence-based algorithms
B. Mental shortcuts used to make quick decisions
C. Random guessing
D. Laboratory error
Answer: B
Rationale: Heuristics are cognitive shortcuts; they speed decisions but can introduce bias.
8.
A 70-year-old diabetic presents with unilateral headache, jaw claudication, and vision changes. Which lab
should you order immediately?
A. ESR
B. Fasting glucose
C. PSA
D. BNP
Answer: A
Rationale: Symptoms suggest giant cell arteritis; elevated ESR supports diagnosis, and prompt treatment is
needed to prevent blindness.
9.
