COMSAE Phase 1 Form 115 Practice Exam NBOME
COMLEX Level 1 – High Yield Questions 2025 | 2026 |
Verified Answers with Detailed Rationales 140
Questions – Instant Download PDF Format
Q1. A 24-year-old male presents with acute onset of severe right lower quadrant
pain, nausea, and fever. Physical exam reveals McBurney's point tenderness.
Which structure is most likely inflamed?
A) Cecum
B) Appendix
C) Ileum
D) Sigmoid colon
Correct answer: B
Rationale: Acute appendicitis classically presents with periumbilical pain
migrating to RLQ (McBurney's point), nausea, fever, and localized tenderness. The
appendix is a blind-ended tube arising from the cecum; inflammation causes
localized peritonitis at McBurney's point.
Q2. A 45-year-old female with type 2 diabetes presents with polyuria, polydipsia,
and blurred vision. Laboratory studies show hyperglycemia. Which hormone
deficiency is primarily responsible for her symptoms?
A) Glucagon
B) Insulin
C) Cortisol
D) Epinephrine
Correct answer: B
Rationale: Insulin deficiency or resistance in type 2 diabetes leads to
hyperglycemia, causing osmotic diuresis (polyuria), dehydration (polydipsia), and
lens osmotic changes (blurred vision). Glucagon raises glucose; cortisol and
epinephrine are counterregulatory hormones.
,Q3. Which cranial nerve is tested by asking a patient to shrug their shoulders
against resistance?
A) CN IX (Glossopharyngeal)
B) CN X (Vagus)
C) CN XI (Spinal accessory)
D) CN XII (Hypoglossal)
Correct answer: C
Rationale: CN XI innervates the sternocleidomastoid and trapezius muscles.
Shoulder shrug against resistance tests trapezius function. CN IX/X test gag reflex;
CN XII tests tongue protrusion.
Q4. A 60-year-old male with chronic alcohol use presents with confusion, ataxia,
and ophthalmoplegia. Which vitamin deficiency is most likely?
A) Vitamin B1 (Thiamine)
B) Vitamin B12 (Cobalamin)
C) Vitamin C (Ascorbic acid)
D) Vitamin D (Cholecalciferol)
Correct answer: A
Rationale: Wernicke encephalopathy (confusion, ataxia, ophthalmoplegia) results
from thiamine deficiency, common in chronic alcoholism due to poor intake,
malabsorption, and impaired utilization.
Q5. A 55-year-old male presents with crushing substernal chest pain radiating to
the left arm, diaphoresis, and nausea. ECG shows ST-segment elevation in leads II,
III, and aVF. Which coronary artery is most likely occluded?
A) Left anterior descending (LAD)
B) Left circumflex (LCx)
C) Right coronary artery (RCA)
D) Posterior descending artery (PDA)
Correct answer: C
Rationale: Inferior wall MI (ST elevation in II, III, aVF) is typically caused by
RCA occlusion. LAD occlusion causes anterior MI (V1-V4); LCx causes lateral
MI (I, aVL, V5-V6); PDA is usually a branch of RCA.
,Q6. A 24-year-old male presents with a cough and night sweats. A chest X-ray
shows a cavitary lesion in the right upper lobe. Sputum culture grows acid-fast
bacilli. Which cytokine is primarily responsible for the formation of the
granulomas seen in this patient?
A) IL-4
B) IL-10
C) IFN-gamma
D) IL-5
Correct answer: C
Rationale: Macrophages present antigen to CD4+ T-cells, which secrete IL-12 to
induce Th1 differentiation. Th1 cells then secrete IFN-gamma to activate
macrophages, leading to granuloma formation in M. tuberculosis infection.
Q7. A 24-year-old woman presents with fever, fatigue, and pallor. Laboratory tests
reveal hemoglobin of 8 g/dL, MCV 70 fL, and serum ferritin of 5 ng/mL. What is
the most likely diagnosis?
A) Vitamin B12 deficiency
B) Iron deficiency anemia
C) Anemia of chronic disease
D) Thalassemia trait
Correct answer: B
Rationale: Microcytic anemia (MCV <80 fL) with very low ferritin (<15 ng/mL)
is diagnostic of iron deficiency anemia. B12 deficiency causes macrocytic anemia.
Anemia of chronic disease typically shows normal or high ferritin. Thalassemia
trait has normal or elevated ferritin.
Q8. A 68-year-old male with hypertension and diabetes presents with sudden onset
of right-sided weakness and aphasia. CT head without contrast shows no
hemorrhage. What is the most appropriate next step if symptoms began 2 hours
ago?
A) Aspirin 325 mg
B) IV tissue plasminogen activator (tPA)
C) Heparin drip
D) Carotid endarterectomy
Correct answer: B
, Rationale: For ischemic stroke within 3-4.5 hours of symptom onset, IV tPA is
indicated if no contraindications. Aspirin is given after tPA or >4.5 hours. Heparin
is not first-line. Carotid endarterectomy is for secondary prevention after
stabilization.
Q9. A 32-year-old pregnant woman at 28 weeks gestation presents with new-onset
hypertension (150/95 mmHg) and proteinuria (300 mg/24h). She denies headaches
or visual changes. What is the most likely diagnosis?
A) Gestational hypertension
B) Chronic hypertension
C) Preeclampsia
D) HELLP syndrome
Correct answer: C
Rationale: Preeclampsia is defined as new-onset hypertension after 20 weeks
gestation with proteinuria or end-organ dysfunction. Gestational hypertension lacks
proteinuria. Chronic hypertension predates pregnancy. HELLP syndrome includes
hemolysis, elevated liver enzymes, low platelets – not described here.
Q10. A 55-year-old male with a history of heavy alcohol use presents with
jaundice, ascites, and asterixis. Laboratory tests reveal elevated AST 120 U/L,
ALT 60 U/L, and total bilirubin 5 mg/dL. Which of the following is the most likely
diagnosis?
A) Viral hepatitis
B) Alcoholic hepatitis
C) Nonalcoholic fatty liver disease
D) Primary biliary cholangitis
Correct answer: B
Rationale: Alcoholic hepatitis typically presents with AST:ALT ratio >1.5 (often
>2), jaundice, ascites, and asterixis in a heavy drinker. Viral hepatitis often has
higher ALT. NAFLD is usually asymptomatic. Primary biliary cholangitis presents
with cholestatic pattern and anti-mitochondrial antibodies.
Q11. A 28-year-old male presents with palpitations, heat intolerance, and weight
loss despite increased appetite. On exam, he has a fine tremor, tachycardia, and a
COMLEX Level 1 – High Yield Questions 2025 | 2026 |
Verified Answers with Detailed Rationales 140
Questions – Instant Download PDF Format
Q1. A 24-year-old male presents with acute onset of severe right lower quadrant
pain, nausea, and fever. Physical exam reveals McBurney's point tenderness.
Which structure is most likely inflamed?
A) Cecum
B) Appendix
C) Ileum
D) Sigmoid colon
Correct answer: B
Rationale: Acute appendicitis classically presents with periumbilical pain
migrating to RLQ (McBurney's point), nausea, fever, and localized tenderness. The
appendix is a blind-ended tube arising from the cecum; inflammation causes
localized peritonitis at McBurney's point.
Q2. A 45-year-old female with type 2 diabetes presents with polyuria, polydipsia,
and blurred vision. Laboratory studies show hyperglycemia. Which hormone
deficiency is primarily responsible for her symptoms?
A) Glucagon
B) Insulin
C) Cortisol
D) Epinephrine
Correct answer: B
Rationale: Insulin deficiency or resistance in type 2 diabetes leads to
hyperglycemia, causing osmotic diuresis (polyuria), dehydration (polydipsia), and
lens osmotic changes (blurred vision). Glucagon raises glucose; cortisol and
epinephrine are counterregulatory hormones.
,Q3. Which cranial nerve is tested by asking a patient to shrug their shoulders
against resistance?
A) CN IX (Glossopharyngeal)
B) CN X (Vagus)
C) CN XI (Spinal accessory)
D) CN XII (Hypoglossal)
Correct answer: C
Rationale: CN XI innervates the sternocleidomastoid and trapezius muscles.
Shoulder shrug against resistance tests trapezius function. CN IX/X test gag reflex;
CN XII tests tongue protrusion.
Q4. A 60-year-old male with chronic alcohol use presents with confusion, ataxia,
and ophthalmoplegia. Which vitamin deficiency is most likely?
A) Vitamin B1 (Thiamine)
B) Vitamin B12 (Cobalamin)
C) Vitamin C (Ascorbic acid)
D) Vitamin D (Cholecalciferol)
Correct answer: A
Rationale: Wernicke encephalopathy (confusion, ataxia, ophthalmoplegia) results
from thiamine deficiency, common in chronic alcoholism due to poor intake,
malabsorption, and impaired utilization.
Q5. A 55-year-old male presents with crushing substernal chest pain radiating to
the left arm, diaphoresis, and nausea. ECG shows ST-segment elevation in leads II,
III, and aVF. Which coronary artery is most likely occluded?
A) Left anterior descending (LAD)
B) Left circumflex (LCx)
C) Right coronary artery (RCA)
D) Posterior descending artery (PDA)
Correct answer: C
Rationale: Inferior wall MI (ST elevation in II, III, aVF) is typically caused by
RCA occlusion. LAD occlusion causes anterior MI (V1-V4); LCx causes lateral
MI (I, aVL, V5-V6); PDA is usually a branch of RCA.
,Q6. A 24-year-old male presents with a cough and night sweats. A chest X-ray
shows a cavitary lesion in the right upper lobe. Sputum culture grows acid-fast
bacilli. Which cytokine is primarily responsible for the formation of the
granulomas seen in this patient?
A) IL-4
B) IL-10
C) IFN-gamma
D) IL-5
Correct answer: C
Rationale: Macrophages present antigen to CD4+ T-cells, which secrete IL-12 to
induce Th1 differentiation. Th1 cells then secrete IFN-gamma to activate
macrophages, leading to granuloma formation in M. tuberculosis infection.
Q7. A 24-year-old woman presents with fever, fatigue, and pallor. Laboratory tests
reveal hemoglobin of 8 g/dL, MCV 70 fL, and serum ferritin of 5 ng/mL. What is
the most likely diagnosis?
A) Vitamin B12 deficiency
B) Iron deficiency anemia
C) Anemia of chronic disease
D) Thalassemia trait
Correct answer: B
Rationale: Microcytic anemia (MCV <80 fL) with very low ferritin (<15 ng/mL)
is diagnostic of iron deficiency anemia. B12 deficiency causes macrocytic anemia.
Anemia of chronic disease typically shows normal or high ferritin. Thalassemia
trait has normal or elevated ferritin.
Q8. A 68-year-old male with hypertension and diabetes presents with sudden onset
of right-sided weakness and aphasia. CT head without contrast shows no
hemorrhage. What is the most appropriate next step if symptoms began 2 hours
ago?
A) Aspirin 325 mg
B) IV tissue plasminogen activator (tPA)
C) Heparin drip
D) Carotid endarterectomy
Correct answer: B
, Rationale: For ischemic stroke within 3-4.5 hours of symptom onset, IV tPA is
indicated if no contraindications. Aspirin is given after tPA or >4.5 hours. Heparin
is not first-line. Carotid endarterectomy is for secondary prevention after
stabilization.
Q9. A 32-year-old pregnant woman at 28 weeks gestation presents with new-onset
hypertension (150/95 mmHg) and proteinuria (300 mg/24h). She denies headaches
or visual changes. What is the most likely diagnosis?
A) Gestational hypertension
B) Chronic hypertension
C) Preeclampsia
D) HELLP syndrome
Correct answer: C
Rationale: Preeclampsia is defined as new-onset hypertension after 20 weeks
gestation with proteinuria or end-organ dysfunction. Gestational hypertension lacks
proteinuria. Chronic hypertension predates pregnancy. HELLP syndrome includes
hemolysis, elevated liver enzymes, low platelets – not described here.
Q10. A 55-year-old male with a history of heavy alcohol use presents with
jaundice, ascites, and asterixis. Laboratory tests reveal elevated AST 120 U/L,
ALT 60 U/L, and total bilirubin 5 mg/dL. Which of the following is the most likely
diagnosis?
A) Viral hepatitis
B) Alcoholic hepatitis
C) Nonalcoholic fatty liver disease
D) Primary biliary cholangitis
Correct answer: B
Rationale: Alcoholic hepatitis typically presents with AST:ALT ratio >1.5 (often
>2), jaundice, ascites, and asterixis in a heavy drinker. Viral hepatitis often has
higher ALT. NAFLD is usually asymptomatic. Primary biliary cholangitis presents
with cholestatic pattern and anti-mitochondrial antibodies.
Q11. A 28-year-old male presents with palpitations, heat intolerance, and weight
loss despite increased appetite. On exam, he has a fine tremor, tachycardia, and a
