A 38-year-old woman presents with BP 168/104 mmHg on two separate occasions. She reports headaches and palpitations for 3 months. Physical examination reveals no abdominal bruits or signs of Cushing syndrome. Serum electrolytes are normal. Urinalysis shows no proteinuria. What is the most appropriate next step in management?

Explanation

## Clinical Context This patient presents with newly diagnosed hypertension (Stage 2) with symptoms suggestive of catecholamine excess (headaches, palpitations). The clinical presentation raises concern for secondary hypertension, specifically pheochromocytoma. ## Diagnostic Approach to Secondary Hypertension **Key Point:** In a young patient with hypertension, symptoms of catecholamine excess, and normal renal function/urinalysis, pheochromocytoma must be excluded before initiating antihypertensive therapy. **High-Yield:** The gold standard screening test for pheochromocytoma is **24-hour urinary metanephrines** or **plasma free metanephrines** (sensitivity >95%). These should be obtained BEFORE starting antihypertensives, as some agents may interfere with testing. ## Why This Step Is Correct 1. **Clinical red flags present:** - Young age (38 years) - Episodic symptoms (headaches, palpitations) - Significant hypertension on first presentation - No signs of primary renal disease (normal UA, normal electrolytes) 2. **Biochemical testing precedes imaging:** Plasma or urinary metanephrines are the first-line biochemical test. Only if positive should imaging (CT/MRI abdomen) follow. 3. **Timing matters:** Testing should occur before starting therapy to avoid false negatives. ## Differential Diagnosis of Secondary Hypertension in Young Adults | Condition | Key Screening Test | Clinical Clue | |-----------|-------------------|---------------| | Pheochromocytoma | 24-h urine metanephrines or plasma free metanephrines | Episodic symptoms, diaphoresis, palpitations | | Primary hyperaldosteronism | Plasma aldosterone/renin ratio | Hypokalemia, metabolic alkalosis | | Renal artery stenosis | Renal artery Doppler or CTA | Abdominal bruit, young age, flash pulmonary edema | | Cushing syndrome | 24-h urine free cortisol or dexamethasone suppression test | Central obesity, purple striae, proximal weakness | **Clinical Pearl:** The triad of pheochromocytoma is **sudden-onset hypertension + severe headache + profuse sweating**. This patient has 2 of 3 components. **Mnemonic — PHEOCHROMOCYTOMA SCREENING:** **MANE** = **M**etanephrines (urine 24-h or plasma free), **A**ddress imaging only if positive, **N**ormalize BP after diagnosis, **E**xamine for MEN syndromes (MEN 2A/2B, NF1).