A 52-year-old man from Delhi presents with hypertension detected on routine screening. His BP is 148/92 mmHg on two separate occasions. He has no symptoms, normal renal function, and normal serum electrolytes. What is the most common cause of hypertension in this patient?

Explanation

## Epidemiology of Hypertension **Key Point:** Essential (primary) hypertension accounts for 90–95% of all hypertension cases in the general population, making it by far the most common cause. ### Prevalence Data | Type | Prevalence | Key Features | |------|-----------|---------------| | Essential hypertension | 90–95% | No identifiable secondary cause; multifactorial (genetic, environmental) | | Renovascular hypertension | 1–5% | Renal artery stenosis; younger or older patients with sudden onset | | Primary hyperaldosteronism | 5–10% | Hypokalemia, metabolic alkalosis; accounts for ~5% of secondary HTN | | Pheochromocytoma | <1% | Episodic symptoms (sweating, palpitations, headache); rare | ### Clinical Clues for Essential HTN **High-Yield:** In this patient: - No secondary features (normal renal function, normal electrolytes) - Gradual onset, asymptomatic - Middle-aged (52 years) - No family history of early renal disease or sudden HTN onset These features are classic for essential hypertension. ### Why Secondary Causes Are Less Likely Here **Clinical Pearl:** Secondary hypertension should be suspected when: - Age of onset <30 or >55 years with new HTN - Sudden worsening of previously controlled HTN - Hypokalemia, metabolic alkalosis, or renal impairment present - Episodic symptoms (pheochromocytoma) or abdominal bruit (renovascular) This patient has none of these red flags. [cite:Harrison 21e Ch 297]