Internal Medicine
Internal Medicine tests structured diagnostic reasoning across common adult presentations such as chest pain, dyspnea, edema, fever, polyuria, and altered consciousness. The exam emphasizes hypertension, diabetes, heart failure, chronic kidney disease, and anemia, and expects you to link mechanism to first-line management.
Core rules
- Confirm the diagnosis with the right test before chronic therapy: HbA1c or repeat glucose for diabetes; ECG and troponin for ACS; BNP is supportive, not diagnostic, for heart failure.
- Stage CKD by eGFR and albuminuria; adjust renally cleared drugs and avoid metformin when eGFR is below 30 mL/min/1.73 m².
- In heart failure with reduced ejection fraction, start guideline-directed therapy (ACE inhibitor/ARB/ARNI, beta-blocker, mineralocorticoid antagonist, SGLT2 inhibitor) unless contraindicated.
Worked example
A 55-year-old man reports polyuria and weight loss. Random plasma glucose is 250 mg/dL (13.9 mmol/L), ketones are negative, eGFR is 75, and BMI is 28. Symptoms plus random glucose ≥200 mg/dL diagnose diabetes. Start lifestyle advice and metformin; check HbA1c, blood pressure, lipids, urine albumin-to-creatinine ratio, and feet. Insulin is not required without catabolic features or very high HbA1c.
Traps
- Diagnosing diabetes from a random glucose in an asymptomatic patient without repeat testing.
- Starting metformin in severe renal impairment or during acute illness.
- Missing a foot ulcer or albuminuria because glucose was the only focus.