COMLEX-USA Level 1 Exam Questions With
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download
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1. A 25-year-old male presents with acute onset of severe chest pain
radiating to the back. Blood pressure is unequal in both arms.
Which of the following is the most likely diagnosis?
A. Myocardial infarction
B. Aortic dissection
C. Pulmonary embolism
D. Pericarditis
This presentation is classic for aortic dissection, especially with unequal
arm pressures and tearing chest pain.
2. A patient presents with fatigue, pallor, and koilonychia. Laboratory
studies reveal microcytic anemia. The most likely cause is:
A. Vitamin B12 deficiency
B. Iron deficiency
C. Folate deficiency
D. Aplastic anemia
Microcytic anemia with koilonychia strongly suggests iron deficiency.
3. A 35-year-old female presents with heat intolerance, palpitations,
and weight loss. Physical exam shows exophthalmos. Lab studies
reveal low TSH. Which condition is most likely?
, A. Hypothyroidism
B. Subacute thyroiditis
C. Graves’ disease
D. Hashimoto’s thyroiditis
Low TSH with hyperthyroid symptoms and exophthalmos is diagnostic
for Graves’ disease.
4. A 60-year-old male with history of smoking presents with
hematuria. Which of the following is the most likely diagnosis?
A. Bladder cancer
B. Kidney stones
C. Prostate cancer
D. Urinary tract infection
Painless hematuria in an older male smoker is highly suggestive of
bladder cancer.
5. A patient presents with a sudden, severe headache described as
"the worst headache of my life." The first test of choice is:
A. MRI brain
B. CT scan without contrast
C. Lumbar puncture
D. EEG
Non-contrast CT is the first-line imaging for suspected subarachnoid
hemorrhage.
6. A 40-year-old male presents with severe epigastric pain radiating
to the back, elevated serum lipase, and amylase. Most likely
diagnosis?
A. Peptic ulcer disease
, B. Cholecystitis
C. Acute pancreatitis
D. Gastritis
Elevated amylase and lipase with epigastric pain radiating to the back
indicate acute pancreatitis.
7. A 7-year-old child presents with a rash starting on the face and
spreading downward, with Koplik spots in the oral mucosa. Most
likely diagnosis?
A. Rubella
B. Scarlet fever
C. Measles (Rubeola)
D. Fifth disease
Koplik spots are pathognomonic for measles.
8. A 28-year-old female presents with dysuria and urinary frequency.
Urine dipstick shows leukocyte esterase and nitrites. The most
likely pathogen is:
A. Streptococcus pyogenes
B. Escherichia coli
C. Staphylococcus aureus
D. Klebsiella pneumoniae
E. coli is the most common cause of uncomplicated urinary tract
infections.
9. A 55-year-old male presents with progressive shortness of breath
and bibasilar crackles. Chest X-ray shows honeycombing. Most
likely diagnosis:
A. COPD
, B. Pulmonary edema
C. Idiopathic pulmonary fibrosis
D. Pneumothorax
Honeycombing on imaging is characteristic of idiopathic pulmonary
fibrosis.
10. A patient presents with jaundice, dark urine, and elevated
unconjugated bilirubin. Which type of jaundice is this?
A. Conjugated
B. Unconjugated
C. Mixed
D. Obstructive
Elevated unconjugated bilirubin suggests hemolysis or impaired bilirubin
conjugation.
11. A 65-year-old female presents with difficulty initiating
urination, weak stream, and dribbling. Most likely cause?
A. Cystitis
B. Benign prostatic hyperplasia
C. Neurogenic bladder
D. Urethral stricture
BPH causes obstruction of urinary flow; note: in females, urethral
obstruction is rare—this could also suggest other causes, but BPH
equivalent in males is most common.
12. Which artery is most commonly affected in an ischemic
stroke?
A. Posterior cerebral artery
B. Middle cerebral artery
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download
1. A 25-year-old male presents with acute onset of severe chest pain
radiating to the back. Blood pressure is unequal in both arms.
Which of the following is the most likely diagnosis?
A. Myocardial infarction
B. Aortic dissection
C. Pulmonary embolism
D. Pericarditis
This presentation is classic for aortic dissection, especially with unequal
arm pressures and tearing chest pain.
2. A patient presents with fatigue, pallor, and koilonychia. Laboratory
studies reveal microcytic anemia. The most likely cause is:
A. Vitamin B12 deficiency
B. Iron deficiency
C. Folate deficiency
D. Aplastic anemia
Microcytic anemia with koilonychia strongly suggests iron deficiency.
3. A 35-year-old female presents with heat intolerance, palpitations,
and weight loss. Physical exam shows exophthalmos. Lab studies
reveal low TSH. Which condition is most likely?
, A. Hypothyroidism
B. Subacute thyroiditis
C. Graves’ disease
D. Hashimoto’s thyroiditis
Low TSH with hyperthyroid symptoms and exophthalmos is diagnostic
for Graves’ disease.
4. A 60-year-old male with history of smoking presents with
hematuria. Which of the following is the most likely diagnosis?
A. Bladder cancer
B. Kidney stones
C. Prostate cancer
D. Urinary tract infection
Painless hematuria in an older male smoker is highly suggestive of
bladder cancer.
5. A patient presents with a sudden, severe headache described as
"the worst headache of my life." The first test of choice is:
A. MRI brain
B. CT scan without contrast
C. Lumbar puncture
D. EEG
Non-contrast CT is the first-line imaging for suspected subarachnoid
hemorrhage.
6. A 40-year-old male presents with severe epigastric pain radiating
to the back, elevated serum lipase, and amylase. Most likely
diagnosis?
A. Peptic ulcer disease
, B. Cholecystitis
C. Acute pancreatitis
D. Gastritis
Elevated amylase and lipase with epigastric pain radiating to the back
indicate acute pancreatitis.
7. A 7-year-old child presents with a rash starting on the face and
spreading downward, with Koplik spots in the oral mucosa. Most
likely diagnosis?
A. Rubella
B. Scarlet fever
C. Measles (Rubeola)
D. Fifth disease
Koplik spots are pathognomonic for measles.
8. A 28-year-old female presents with dysuria and urinary frequency.
Urine dipstick shows leukocyte esterase and nitrites. The most
likely pathogen is:
A. Streptococcus pyogenes
B. Escherichia coli
C. Staphylococcus aureus
D. Klebsiella pneumoniae
E. coli is the most common cause of uncomplicated urinary tract
infections.
9. A 55-year-old male presents with progressive shortness of breath
and bibasilar crackles. Chest X-ray shows honeycombing. Most
likely diagnosis:
A. COPD
, B. Pulmonary edema
C. Idiopathic pulmonary fibrosis
D. Pneumothorax
Honeycombing on imaging is characteristic of idiopathic pulmonary
fibrosis.
10. A patient presents with jaundice, dark urine, and elevated
unconjugated bilirubin. Which type of jaundice is this?
A. Conjugated
B. Unconjugated
C. Mixed
D. Obstructive
Elevated unconjugated bilirubin suggests hemolysis or impaired bilirubin
conjugation.
11. A 65-year-old female presents with difficulty initiating
urination, weak stream, and dribbling. Most likely cause?
A. Cystitis
B. Benign prostatic hyperplasia
C. Neurogenic bladder
D. Urethral stricture
BPH causes obstruction of urinary flow; note: in females, urethral
obstruction is rare—this could also suggest other causes, but BPH
equivalent in males is most common.
12. Which artery is most commonly affected in an ischemic
stroke?
A. Posterior cerebral artery
B. Middle cerebral artery
