MCCQE Part 1 Medicine MCQs: Practice Questions With Explanations

Medicine Is a Core Subject Across MCCQE Part 1

Medicine and its subspecialties — cardiology, endocrinology, gastroenterology, respirology, and nephrology among them — make up one of the largest question blocks on MCCQE Part 1. Below are sample vignette-style MCQs grouped by theme, with the correct answer marked and a short explanation.

Cardiovascular Presentations

1. Which triad describes the classic mechanisms predisposing to venous thromboembolism?
A) Charcot's triad  B) Virchow's triad ✅  C) Beck's triad  D) Cushing's triad
Explanation: Virchow's triad — venous stasis, endothelial injury, and hypercoagulability — describes the three mechanisms that predispose to venous thrombosis.

2. A patient with a pericardial effusion presents with hypotension, distended neck veins, and muffled heart sounds. What is this triad called, and what does it suggest?
A) Charcot's triad — cholangitis  B) Beck's triad — cardiac tamponade ✅  C) Cushing's triad — raised ICP  D) Whipple's triad — hypoglycemia
Explanation: Beck's triad — hypotension, jugular venous distension, and muffled heart sounds — is the classic clinical presentation of cardiac tamponade.

3. A patient with rising intracranial pressure develops hypertension, bradycardia, and irregular respirations. What is this reflex called?
A) Beck's triad  B) Cushing's triad (Cushing's reflex) ✅  C) Charcot's triad  D) Virchow's triad
Explanation: Cushing's triad — hypertension, bradycardia, and irregular breathing — reflects the body's response to rising intracranial pressure and signals a neurosurgical emergency.

Endocrine & Metabolic Presentations

4. A patient presents with fatigue, hyperpigmentation, hypotension, hyponatremia, and hyperkalemia. What is the most likely diagnosis?
A) Cushing's syndrome  B) Primary adrenal insufficiency (Addison's disease) ✅  C) SIADH  D) Conn's syndrome
Explanation: Hyperpigmentation with hypotension, hyponatremia, and hyperkalemia is the classic picture of primary adrenal insufficiency, caused by loss of both cortisol and aldosterone.

5. An ECG shows peaked T waves and a widening QRS complex in a patient with acute kidney injury. Which electrolyte abnormality is most likely?
A) Hypokalemia  B) Hyperkalemia ✅  C) Hypercalcemia  D) Hyponatremia
Explanation: Peaked T waves progressing to a widened QRS are the classic early-to-late ECG changes of hyperkalemia, a recognised complication of acute kidney injury.

Gastrointestinal & Hepatobiliary Presentations

6. A patient with gallstones presents with right upper quadrant pain, fever, and jaundice. What is this triad called, and what does it indicate?
A) Charcot's triad — ascending cholangitis ✅  B) Whipple's triad — insulinoma  C) Virchow's triad — DVT  D) Beck's triad — tamponade
Explanation: Charcot's triad — right upper quadrant pain, fever, and jaundice — is classic for ascending cholangitis, a biliary tract infection usually caused by obstruction.

7. A pleural fluid sample has a pleural-to-serum protein ratio greater than 0.5. Under Light's criteria, how is this effusion classified?
A) Transudate  B) Exudate ✅  C) Hemothorax  D) Chylothorax
Explanation: Light's criteria classify an effusion as exudative if the pleural-to-serum protein ratio exceeds 0.5 (or the LDH ratio exceeds 0.6, or pleural LDH exceeds two-thirds the upper limit of normal serum LDH).

Respiratory Presentations

8. Which organism is the most common cause of community-acquired pneumonia in otherwise healthy adults?
A) Klebsiella pneumoniae  B) Streptococcus pneumoniae ✅  C) Pseudomonas aeruginosa  D) Mycoplasma pneumoniae
Explanation: Streptococcus pneumoniae remains the most common bacterial cause of community-acquired pneumonia overall, though atypical organisms such as Mycoplasma are important in younger, otherwise healthy patients.

Keep Practicing

These are just a sample. For the full set of MCCQE Part 1 Medicine questions, see HighYield's complete MCCQE Part 1 question bank, or read our MCCQE Part 1 syllabus and pass rate guide for the bigger picture.