Comprehensive Osteopathic Medical Licensing
Examination of the United States (COMLEX-
USA) Practice Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. A 45-year-old man presents with acute epigastric pain radiating to the
back after alcohol use. Serum amylase and lipase are elevated. What is the
most likely diagnosis?
A. Cholecystitis
B. Acute pancreatitis
C. Peptic ulcer disease
D. Gastritis
Rationale: Elevated amylase and lipase with epigastric pain radiating to
the back indicate acute pancreatitis, commonly from alcohol use or
gallstones._
,2. A 23-year-old woman presents with dysuria and increased urinary
frequency. Urinalysis reveals leukocyte esterase and nitrites. The causative
organism is most likely:
A. Staphylococcus saprophyticus
B. Escherichia coli
C. Proteus mirabilis
D. Enterococcus faecalis
Rationale: E. coli is the most common cause of urinary tract infection in
young women._
3. A 65-year-old man has resting tremor, rigidity, and bradykinesia. The
neurotransmitter imbalance responsible is:
A. Increased dopamine and decreased acetylcholine
B. Increased serotonin and dopamine
C. Decreased dopamine and increased acetylcholine
D. Decreased serotonin and norepinephrine
Rationale: Parkinson’s disease involves loss of dopaminergic neurons in
the substantia nigra leading to dopamine deficiency and relative
acetylcholine excess._
4. A newborn presents with continuous “machinery-like” murmur at the
left infraclavicular area. What congenital condition does this describe?
A. Atrial septal defect
,B. Patent ductus arteriosus
C. Ventricular septal defect
D. Coarctation of the aorta
Rationale: A continuous murmur at the left infraclavicular region is classic
for patent ductus arteriosus due to persistent connection between the
aorta and pulmonary artery._
5. A patient with chronic obstructive pulmonary disease (COPD) has
chronic CO₂ retention. Which compensation occurs?
A. Respiratory alkalosis
B. Metabolic compensation with increased HCO₃⁻
C. Respiratory acidosis without compensation
D. Decreased renal HCO₃⁻ reabsorption
Rationale: The kidneys retain bicarbonate to compensate for chronic CO₂
retention in COPD._
6. A 6-year-old develops a sore throat followed by a sandpaper-like rash
and strawberry tongue. The causative organism produces:
A. Erythrogenic exotoxin
B. Endotoxin
C. Exfoliative toxin
D. Tetanospasmin
, Rationale: Scarlet fever from Streptococcus pyogenes is caused by
erythrogenic exotoxin, a superantigen._
7. A 30-year-old woman with hyperthyroidism presents with
exophthalmos and pretibial myxedema. What is the underlying
mechanism?
A. TSH-secreting pituitary adenoma
B. Autoantibody stimulation of TSH receptors
C. Thyroid carcinoma
D. Iodine deficiency
Rationale: Graves disease is an autoimmune condition where IgG
antibodies stimulate TSH receptors leading to thyroid hormone
overproduction._
8. A 25-year-old man presents with urethritis after unprotected sex. Gram
stain shows gram-negative diplococci. Which is the best treatment?
A. Azithromycin alone
B. Doxycycline alone
C. Ceftriaxone plus doxycycline
D. Ciprofloxacin
Rationale: Gonorrhea (Neisseria gonorrhoeae) requires ceftriaxone plus
doxycycline to cover possible Chlamydia coinfection._
Examination of the United States (COMLEX-
USA) Practice Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. A 45-year-old man presents with acute epigastric pain radiating to the
back after alcohol use. Serum amylase and lipase are elevated. What is the
most likely diagnosis?
A. Cholecystitis
B. Acute pancreatitis
C. Peptic ulcer disease
D. Gastritis
Rationale: Elevated amylase and lipase with epigastric pain radiating to
the back indicate acute pancreatitis, commonly from alcohol use or
gallstones._
,2. A 23-year-old woman presents with dysuria and increased urinary
frequency. Urinalysis reveals leukocyte esterase and nitrites. The causative
organism is most likely:
A. Staphylococcus saprophyticus
B. Escherichia coli
C. Proteus mirabilis
D. Enterococcus faecalis
Rationale: E. coli is the most common cause of urinary tract infection in
young women._
3. A 65-year-old man has resting tremor, rigidity, and bradykinesia. The
neurotransmitter imbalance responsible is:
A. Increased dopamine and decreased acetylcholine
B. Increased serotonin and dopamine
C. Decreased dopamine and increased acetylcholine
D. Decreased serotonin and norepinephrine
Rationale: Parkinson’s disease involves loss of dopaminergic neurons in
the substantia nigra leading to dopamine deficiency and relative
acetylcholine excess._
4. A newborn presents with continuous “machinery-like” murmur at the
left infraclavicular area. What congenital condition does this describe?
A. Atrial septal defect
,B. Patent ductus arteriosus
C. Ventricular septal defect
D. Coarctation of the aorta
Rationale: A continuous murmur at the left infraclavicular region is classic
for patent ductus arteriosus due to persistent connection between the
aorta and pulmonary artery._
5. A patient with chronic obstructive pulmonary disease (COPD) has
chronic CO₂ retention. Which compensation occurs?
A. Respiratory alkalosis
B. Metabolic compensation with increased HCO₃⁻
C. Respiratory acidosis without compensation
D. Decreased renal HCO₃⁻ reabsorption
Rationale: The kidneys retain bicarbonate to compensate for chronic CO₂
retention in COPD._
6. A 6-year-old develops a sore throat followed by a sandpaper-like rash
and strawberry tongue. The causative organism produces:
A. Erythrogenic exotoxin
B. Endotoxin
C. Exfoliative toxin
D. Tetanospasmin
, Rationale: Scarlet fever from Streptococcus pyogenes is caused by
erythrogenic exotoxin, a superantigen._
7. A 30-year-old woman with hyperthyroidism presents with
exophthalmos and pretibial myxedema. What is the underlying
mechanism?
A. TSH-secreting pituitary adenoma
B. Autoantibody stimulation of TSH receptors
C. Thyroid carcinoma
D. Iodine deficiency
Rationale: Graves disease is an autoimmune condition where IgG
antibodies stimulate TSH receptors leading to thyroid hormone
overproduction._
8. A 25-year-old man presents with urethritis after unprotected sex. Gram
stain shows gram-negative diplococci. Which is the best treatment?
A. Azithromycin alone
B. Doxycycline alone
C. Ceftriaxone plus doxycycline
D. Ciprofloxacin
Rationale: Gonorrhea (Neisseria gonorrhoeae) requires ceftriaxone plus
doxycycline to cover possible Chlamydia coinfection._
