What investigations and management are recommended for young patients with hypertension, including tests for cortisol, aldosterone, urine (urinary) pheochromocytoma (catecholamine), and urine protein?

Investigations for Young Hypertensive Patients

All young patients with confirmed hypertension (under age 40) should undergo comprehensive screening for secondary causes, as the prevalence is approximately 30% in this population, with primary aldosteronism being the most common etiology. 1, 2

Initial Essential Laboratory Tests

Every young hypertensive patient requires the following baseline investigations:

• Urinalysis and urine protein assessment (dipstick or albumin/creatinine ratio) to detect renal parenchymal disease, which accounts for 34-79% of secondary hypertension in young patients 3, 1
• Serum creatinine and estimated GFR to evaluate kidney function 3, 1
• Serum electrolytes (sodium and potassium) as hypokalemia suggests primary aldosteronism, though most patients with aldosteronism are normokalemic 3, 4
• Lipid profile and fasting glucose or HbA1c for cardiovascular risk stratification 3
• 12-lead ECG to detect left ventricular hypertrophy (target organ damage) 3

Screening for Specific Secondary Causes

Primary Aldosteronism Screening (HIGHEST PRIORITY)

Measure aldosterone-to-renin ratio (ARR) in ALL young hypertensive patients, as primary aldosteronism affects 5-20% of hypertensive individuals and was the most common secondary cause (54.8%) in recent studies. 3, 4, 2

• This test should be performed even without hypokalemia, as only a minority present with low potassium 4, 5
• The 2024 ESC guidelines specifically recommend ARR screening in all adults with confirmed hypertension (Class IIa recommendation) 3
• Primary aldosteronism is particularly common in young adults aged 30-40 years 2

Pheochromocytoma/Paraganglioma Screening

Measure 24-hour urinary fractionated metanephrines and catecholamines (or plasma free metanephrines) if any of the following are present: 3, 1

• Paroxysmal hypertension with headaches, palpitations, sweating, or pallor 3, 5
• Severe or resistant hypertension 5
• Adrenal mass discovered on imaging 5
• Family history of pheochromocytoma or genetic syndromes 5

Pheochromocytoma accounts for 3.75-5.9% of secondary hypertension in young adults 4, 2

Cushing Syndrome Screening

Screen for hypercortisolism with late-night salivary cortisol or 24-hour urinary free cortisol if clinical features suggest Cushing syndrome: 3

• Truncal obesity, purple striae, glucose intolerance, easy bruising 3
• Cushing syndrome accounts for approximately 7.5% of secondary endocrine hypertension in young patients 4

Additional Imaging Studies

Renal ultrasound with Doppler should be performed in:

• All children and adolescents with confirmed hypertension 1, 6
• Young adults with abnormal urinalysis, elevated creatinine, or clinical suspicion of renovascular disease 1, 6
• Renovascular hypertension (particularly fibromuscular dysplasia in young women) accounts for 12-18% of secondary hypertension in young patients 1, 2

Echocardiography is indicated when:

• Considering pharmacologic treatment, to assess for left ventricular hypertrophy 1
• Evaluating target organ damage severity 3

Clinical Context for Screening Intensity

The following factors increase the likelihood of secondary hypertension and warrant more aggressive screening: 2

• Female sex
• Body mass index <25 kg/m² (lean patients)
• Absence of family history of hypertension
• Hypokalemia (even if mild or diuretic-induced)
• Requirement for ≥2 antihypertensive medications
• Presence of diabetes

Important caveat: Blood pressure level alone does not predict secondary hypertension—patients with BP <160/100 mmHg have similar prevalence of secondary causes as those with higher pressures 2

Confirmatory Testing Before Extensive Workup

Obtain ambulatory blood pressure monitoring (ABPM) to confirm true hypertension and exclude white coat hypertension before proceeding with extensive secondary cause evaluation. 1

• This prevents unnecessary testing in patients without sustained hypertension
• ABPM is particularly important in young patients where false-positive clinic readings are common 3

Age-Specific Considerations

For patients under age 6 years: Renal ultrasound is mandatory as structural renal abnormalities are the predominant cause 3

For patients 18-30 years: Consider renovascular disease (fibromuscular dysplasia) and monogenic disorders more prominently 3, 6

For patients 30-40 years: Primary aldosteronism becomes increasingly prevalent and should be the primary screening focus 2