General Medicine: High-Yield Reasoning for the MOHAP Exam
Core concepts to master
General Medicine questions reward a structured approach: recognise the syndrome, identify the most likely diagnosis, then choose the safest next step. Prioritise cardiovascular medicine (acute coronary syndrome, heart failure, atrial fibrillation, hypertensive emergencies), endocrinology (diabetic ketoacidosis versus hyperosmolar hyperglycaemic state, thyroid disease, adrenal insufficiency), respiratory medicine (asthma versus COPD, pneumonia severity, pulmonary embolism), and acid–base and electrolyte interpretation. Know the criteria that change management: CURB-65 for pneumonia, Wells score logic for thromboembolism, and the anion gap in metabolic acidosis.
Common traps
Questions frequently test the first action rather than the definitive treatment. In suspected acute coronary syndrome, the answer is ECG and aspirin, not thrombolysis. In hyperkalaemia with ECG changes, calcium gluconate protects the myocardium before insulin–dextrose shifts potassium. In DKA, fluids precede insulin and potassium is checked and replaced early. Distinguish "most likely diagnosis" from "most appropriate investigation"; read the stem's final line carefully. Another trap is the patient with normal vital signs but a dangerous condition - pulmonary embolism and early sepsis can present deceptively.
Worked rule of thumb
A 24-year-old with type 1 diabetes presents with vomiting, Kussmaul breathing, glucose 28 mmol/L, pH 7.15, bicarbonate 10, and ketones 4+. Diagnosis: DKA. First step: isotonic saline resuscitation. Check potassium: if below 3.3 mmol/L, replace before starting insulin; if above 5.5, manage hyperkalaemia first. Then fixed-rate insulin infusion with dextrose added when glucose falls. This sequence - fluids, potassium, insulin - is a reliable discriminator in answer options.