17. Secondary hypertension

Question 1

What is secondary hypertension?

Answer 1

80-95% of hypertensive patients are diagnosed with primary/essential hypertension, while 5-20% of hypertensive patients have hypertension secondary to a specific underlying cause

Question 2

What may be the underlying causes of secondary hypertension?

Answer 2

• Renal parenchymal disease
• Renovascular disease (stenosis of renal artery(ies))
• Endocrine diseases
  
  • Hyperthyroidism, pheochromocytoma, hyperaldosteronism, cushing syndrome, acromegaly
• Drugs
  
  • NSAIDs, cheese effect, nasal decongestants, steroids, cocaine
• Obesity and metabolic syndrome
• Coarctation of the aorta

Question 3

How is secondary HTN diagnosed?

Answer 3

Testing for secondary hypertension requires advanced methods and should only be done if we have suspicion of secondary causes as the tests are expensive and take time (otherwise routine examination)

Routine examination:

• Abdominal ausculation for bruits
  
  • If present, may be renal sclerosis
• Lab values
  
  • Creatinin, urea, urinalysis

Advanced examination:

• Angiography
• US
• Cortisol, TSH
• Aldosterone/renin ratio