Endocrinology, Diabetes and Metabolism
Core concepts
Know the diagnostic criteria for diabetes (fasting glucose, HbA1c, OGTT, random with symptoms), the pharmacology of glucose-lowering agents, and the modern emphasis on cardiovascular and renal protection (SGLT2 inhibitors, GLP-1 receptor agonists). Understand thyroid function testing (TSH first, then free T4), thyroid storm and myxoedema coma as emergencies, and the approach to thyroid nodules. Be fluent in adrenal disorders (Addison's, Cushing's, Conn's), calcium metabolism (primary hyperparathyroidism vs malignancy-related hypercalcaemia), and pituitary disease.
Traps
Questions test sick euthyroid patterns and amiodarone-induced thyroid dysfunction. Do not diagnose diabetes on HbA1c alone in pregnancy or haemoglobinopathy. Distinguish DKA (ketosis, acidosis, normal/high potassium but total body depletion) from HHS (hyperosmolality, minimal ketosis). In Addison's, hyperkalaemia and hyponatraemia with hypotension should prompt cortisol and ACTH measurement before steroids if safe - but never delay treatment when unstable.
Rule of thumb
In suspected DKA, start isotonic saline, give insulin after confirming potassium is adequate, and add dextrose when glucose falls - the anion gap, not glucose, marks resolution.
Worked example
A young patient with polyuria, vomiting, and Kussmaul breathing: check ketones, venous blood gas, and potassium; treat with fluids, insulin infusion, and potassium replacement when K⁺ <5.5 mmol/L.