A 34-year-old male presents with profound muscle weakness and recurrent muscle spasms. Laboratory investigation reveals severe hypokalemia (serum potassium 2.4 mmol/L), metabolic alkalosis (bicarbonate 35 mEq/L), and resistant hypertension (BP 172/106 mmHg). Serum aldosterone is markedly elevated, and plasma renin activity is profoundly suppressed. What is the diagnosis?

Answer and explanation

Correct answer: B. Primary Hyperaldosteronism (Conn Syndrome)

  1. Step 1: Primary hyperaldosteronism (Conn syndrome) is caused by autonomous overproduction of aldosterone (most commonly by an adrenal adenoma or bilateral adrenal hyperplasia).
  2. Step 2: Aldosterone stimulates principal cells in the renal cortical collecting tubule to reabsorb sodium and excrete potassium and hydrogen ions, resulting in hypertension, hypokalemia, and metabolic alkalosis with suppressed plasma renin activity (elevated Aldosterone-to-Renin Ratio, ARR).
Answer
Primary Hyperaldosteronism (Conn Syndrome).
Why not the others: 'Renal artery stenosis' leads to renal hypoperfusion, resulting in high renin and high aldosterone (secondary hyperaldosteronism); 'Pheochromocytoma' secretes catecholamines, causing episodic paroxysmal hypertension, headaches, sweating, and palpitations; 'Cushing syndrome' involves glucocorticoid excess.

Practise more Endocrine, Renal and Gastrointestinal Pathology.

Free questions with an explanation for every one, and full timed DHA Dubai mock tests.

All Endocrine, Renal and Gastrointestinal Pathology questionsTake a mock test

More Endocrine, Renal and Gastrointestinal Pathology questions