Primary hyperaldosteronism


  • XS aldosteronism - Na+ retention, hypertension and hypokalaemia
  • Rare (< 1%) causes of hypertension
  • Adrenal adenoma = Conn’s synd = 60% primary hyperaldosteronism (hyperplasia)
  • Adenomas in young women, bilateral hyperplasia in older men



  • ↑ (>30mmol/day) urinary K+ loss → hypokalaemia
  • High aldosterone levels not suppressed by saline or fludrocortisone
  • Suppressed renin activity (beware β-blockers may do similar)
  • Then CT or venous catheterisation

Secondary Hyperaldosteronism

  • XS renin and so angiotensin 2 causing stimulation of zona glomerulosa
  • Causes - accelerated hi BP, renal art stenosis
  • Causes in normal BP = CCF and cirrhosis etc
  • Spironolactone useful in both
  • ACEI (e.g. Captopril ) good for failure


  • Surgery in Conn's
  • Spironolactone (aldosterone antagonist) in hyperplasias (or amiloride - less gynacomastia)

Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS 12/04/23.