COMLEX Level 1 Form 104 practice
Exam With Actual 120 Questions &
Verified Answers,Plus
Rationales/Expert Verified For
Guaranteed Pass Graded A+/
2025/2026 /Latest Update/Instant
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1. A 24-year-old male presents with acute onset right lower quadrant abdominal pain,
nausea, and low-grade fever. Physical examination reveals tenderness at McBurney’s
point. Laboratory studies show leukocytosis. What is the most likely diagnosis?
A. Gastroenteritis
B. Appendicitis
C. Cholecystitis
D. Mesenteric adenitis
Answer: B
Rationale: Acute appendicitis classically presents with periumbilical pain migrating to the
right lower quadrant (McBurney’s point), accompanied by nausea and leukocytosis.
2. A 32-year-old woman presents with fatigue, pallor, and spoon-shaped nails.
Laboratory results show microcytic hypochromic anemia with low serum ferritin.
What is the most likely cause?
A. Vitamin B12 deficiency
B. Iron deficiency anemia
C. Anemia of chronic disease
D. Thalassemia
Answer: B
Rationale: Iron deficiency anemia presents with microcytic hypochromic anemia, low
ferritin, and symptoms such as fatigue and koilonychia.
, 3. A patient with a history of chronic alcohol use presents with confusion, ataxia, and
ophthalmoplegia. What is the first-line treatment?
A. Thiamine
B. Folate
C. Thiamine before glucose
D. Glucose
Answer: C
Rationale: Wernicke’s encephalopathy requires thiamine administration before glucose to
prevent exacerbation of symptoms due to glucose metabolism.
4. A 60-year-old male presents with painless hematuria. He has a 40-pack-year smoking
history. Which is the most likely diagnosis?
A. Benign prostatic hyperplasia
B. Transitional cell carcinoma of the bladder
C. Kidney stone
D. Glomerulonephritis
Answer: B
Rationale: Painless hematuria in older adults, especially with smoking history, suggests
transitional cell carcinoma of the bladder.
5. A 5-year-old child presents with a “slapped cheek” rash on the face and mild fever.
Which virus is responsible?
A. Measles virus
B. Rubella virus
C. Parvovirus B19
D. Varicella-zoster virus
Answer: C
Rationale: Parvovirus B19 causes erythema infectiosum (“slapped cheek” rash) and mild
systemic symptoms in children.
6. A 28-year-old male presents with painful genital ulcers and inguinal
lymphadenopathy. Dark-field microscopy shows spirochetes. What is the causative
organism?
A. Herpes simplex virus
B. Chlamydia trachomatis
C. Treponema pallidum
D. Haemophilus ducreyi
Answer: C
Rationale: Primary syphilis presents with a painless chancre, but this description suggests
spirochetes; Treponema pallidum is identified by dark-field microscopy.
, 7. A 45-year-old woman presents with weight gain, cold intolerance, constipation, and
dry skin. Lab tests reveal elevated TSH and low free T4. What is the most likely
diagnosis?
A. Hyperthyroidism
B. Subclinical hypothyroidism
C. Primary hypothyroidism (Hashimoto’s thyroiditis)
D. Secondary hypothyroidism
Answer: C
Rationale: Elevated TSH with low T4 indicates primary hypothyroidism, commonly caused
by autoimmune Hashimoto’s thyroiditis.
8. A patient presents with sudden-onset, severe chest pain radiating to the back and
unequal blood pressures in both arms. What is the most likely diagnosis?
A. Myocardial infarction
B. Pulmonary embolism
C. Aortic dissection
D. Pneumothorax
Answer: C
Rationale: Acute aortic dissection presents with tearing chest pain radiating to the back
and can cause asymmetrical blood pressures due to involvement of the aortic branches.
9. A 3-year-old boy presents with a barking cough, inspiratory stridor, and low-grade
fever. What is the most likely causative agent?
A. Respiratory syncytial virus
B. Influenza virus
C. Parainfluenza virus
D. Adenovirus
Answer: C
Rationale: Croup (laryngotracheobronchitis) is caused by parainfluenza virus and presents
with barking cough, stridor, and mild fever.
10. A patient with chronic kidney disease presents with bone pain and subperiosteal
resorption on X-ray. Lab tests show elevated PTH and low calcium. What is the
diagnosis?
A. Osteoporosis
B. Osteomalacia
C. Secondary hyperparathyroidism
D. Paget’s disease
, Answer: C
Rationale: CKD causes phosphate retention and decreased vitamin D activation, leading to
secondary hyperparathyroidism and renal osteodystrophy.
11. A newborn presents with jaundice within the first 24 hours of life. Total bilirubin is
elevated, predominantly unconjugated. What is the most likely cause?
A. Physiologic jaundice
B. Breastfeeding jaundice
C. Hemolytic disease of the newborn
D. Biliary atresia
Answer: C
Rationale: Jaundice in the first 24 hours is abnormal and suggests hemolytic disease, such
as Rh or ABO incompatibility.
12. A 16-year-old male presents with recurrent epistaxis and telangiectasias. He also has
a family history of similar symptoms. Which condition is most likely?
A. Hemophilia A
B. Von Willebrand disease
C. Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu)
D. Idiopathic thrombocytopenic purpura
Answer: C
Rationale: HHT presents with mucocutaneous telangiectasias, recurrent nosebleeds, and a
positive family history.
13. A 30-year-old female presents with fatigue, joint pain, and a malar rash. ANA is
positive. What is the most likely diagnosis?
A. Rheumatoid arthritis
B. Scleroderma
C. Systemic lupus erythematosus
D. Dermatomyositis
Answer: C
Rationale: SLE commonly presents with malar rash, arthralgia, fatigue, and positive ANA.
14. A 65-year-old male smoker presents with hemoptysis and weight loss. Chest X-ray
shows a central mass near the hilum. Which type of lung cancer is most likely?
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Small cell carcinoma
D. Large cell carcinoma
Exam With Actual 120 Questions &
Verified Answers,Plus
Rationales/Expert Verified For
Guaranteed Pass Graded A+/
2025/2026 /Latest Update/Instant
Download Pdf
1. A 24-year-old male presents with acute onset right lower quadrant abdominal pain,
nausea, and low-grade fever. Physical examination reveals tenderness at McBurney’s
point. Laboratory studies show leukocytosis. What is the most likely diagnosis?
A. Gastroenteritis
B. Appendicitis
C. Cholecystitis
D. Mesenteric adenitis
Answer: B
Rationale: Acute appendicitis classically presents with periumbilical pain migrating to the
right lower quadrant (McBurney’s point), accompanied by nausea and leukocytosis.
2. A 32-year-old woman presents with fatigue, pallor, and spoon-shaped nails.
Laboratory results show microcytic hypochromic anemia with low serum ferritin.
What is the most likely cause?
A. Vitamin B12 deficiency
B. Iron deficiency anemia
C. Anemia of chronic disease
D. Thalassemia
Answer: B
Rationale: Iron deficiency anemia presents with microcytic hypochromic anemia, low
ferritin, and symptoms such as fatigue and koilonychia.
, 3. A patient with a history of chronic alcohol use presents with confusion, ataxia, and
ophthalmoplegia. What is the first-line treatment?
A. Thiamine
B. Folate
C. Thiamine before glucose
D. Glucose
Answer: C
Rationale: Wernicke’s encephalopathy requires thiamine administration before glucose to
prevent exacerbation of symptoms due to glucose metabolism.
4. A 60-year-old male presents with painless hematuria. He has a 40-pack-year smoking
history. Which is the most likely diagnosis?
A. Benign prostatic hyperplasia
B. Transitional cell carcinoma of the bladder
C. Kidney stone
D. Glomerulonephritis
Answer: B
Rationale: Painless hematuria in older adults, especially with smoking history, suggests
transitional cell carcinoma of the bladder.
5. A 5-year-old child presents with a “slapped cheek” rash on the face and mild fever.
Which virus is responsible?
A. Measles virus
B. Rubella virus
C. Parvovirus B19
D. Varicella-zoster virus
Answer: C
Rationale: Parvovirus B19 causes erythema infectiosum (“slapped cheek” rash) and mild
systemic symptoms in children.
6. A 28-year-old male presents with painful genital ulcers and inguinal
lymphadenopathy. Dark-field microscopy shows spirochetes. What is the causative
organism?
A. Herpes simplex virus
B. Chlamydia trachomatis
C. Treponema pallidum
D. Haemophilus ducreyi
Answer: C
Rationale: Primary syphilis presents with a painless chancre, but this description suggests
spirochetes; Treponema pallidum is identified by dark-field microscopy.
, 7. A 45-year-old woman presents with weight gain, cold intolerance, constipation, and
dry skin. Lab tests reveal elevated TSH and low free T4. What is the most likely
diagnosis?
A. Hyperthyroidism
B. Subclinical hypothyroidism
C. Primary hypothyroidism (Hashimoto’s thyroiditis)
D. Secondary hypothyroidism
Answer: C
Rationale: Elevated TSH with low T4 indicates primary hypothyroidism, commonly caused
by autoimmune Hashimoto’s thyroiditis.
8. A patient presents with sudden-onset, severe chest pain radiating to the back and
unequal blood pressures in both arms. What is the most likely diagnosis?
A. Myocardial infarction
B. Pulmonary embolism
C. Aortic dissection
D. Pneumothorax
Answer: C
Rationale: Acute aortic dissection presents with tearing chest pain radiating to the back
and can cause asymmetrical blood pressures due to involvement of the aortic branches.
9. A 3-year-old boy presents with a barking cough, inspiratory stridor, and low-grade
fever. What is the most likely causative agent?
A. Respiratory syncytial virus
B. Influenza virus
C. Parainfluenza virus
D. Adenovirus
Answer: C
Rationale: Croup (laryngotracheobronchitis) is caused by parainfluenza virus and presents
with barking cough, stridor, and mild fever.
10. A patient with chronic kidney disease presents with bone pain and subperiosteal
resorption on X-ray. Lab tests show elevated PTH and low calcium. What is the
diagnosis?
A. Osteoporosis
B. Osteomalacia
C. Secondary hyperparathyroidism
D. Paget’s disease
, Answer: C
Rationale: CKD causes phosphate retention and decreased vitamin D activation, leading to
secondary hyperparathyroidism and renal osteodystrophy.
11. A newborn presents with jaundice within the first 24 hours of life. Total bilirubin is
elevated, predominantly unconjugated. What is the most likely cause?
A. Physiologic jaundice
B. Breastfeeding jaundice
C. Hemolytic disease of the newborn
D. Biliary atresia
Answer: C
Rationale: Jaundice in the first 24 hours is abnormal and suggests hemolytic disease, such
as Rh or ABO incompatibility.
12. A 16-year-old male presents with recurrent epistaxis and telangiectasias. He also has
a family history of similar symptoms. Which condition is most likely?
A. Hemophilia A
B. Von Willebrand disease
C. Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu)
D. Idiopathic thrombocytopenic purpura
Answer: C
Rationale: HHT presents with mucocutaneous telangiectasias, recurrent nosebleeds, and a
positive family history.
13. A 30-year-old female presents with fatigue, joint pain, and a malar rash. ANA is
positive. What is the most likely diagnosis?
A. Rheumatoid arthritis
B. Scleroderma
C. Systemic lupus erythematosus
D. Dermatomyositis
Answer: C
Rationale: SLE commonly presents with malar rash, arthralgia, fatigue, and positive ANA.
14. A 65-year-old male smoker presents with hemoptysis and weight loss. Chest X-ray
shows a central mass near the hilum. Which type of lung cancer is most likely?
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Small cell carcinoma
D. Large cell carcinoma
