Hyperaldosteronism

Hyperaldosteronism is classically associated with treatment-resistant hypertension, and hypokalaemia. There are 2 types of it:

• Primary - This is known as Conn’s syndrome, and it's where the adrenals produce too much aldosterone, leading to low renin as a result. The 2 main causes of it are:

  • Bilateral adrenal hyperplasia (70%) - most common

  • Adrenal adenoma (30%)

• Secondary - This is due to high renin production. Causes of it include:

  • Renal artery stenosis

  • Renal artery obstruction

  • Renin-secreting tumour

  • HF

Presentation - Polyuria, polydipsia, lethargy, headaches

Investigations

The main investigation to do is Aldosterone and Renin:

• Renin will be low in primary

• Renin will be high in secondary

Other investigations to do include:

• BP

• U&E - Hypernatraemia, Hypokalaemia

• ABG/VBG - Metabolic alkalosis

• CT/MRI - Adrenal adenoma

• Renal doppler US, CT/MR Angiogram - Renal artery stenosis

N.B. Hypernatraemia tends to be a much later sign of Conn's.

Management

• Aldosterone antagonists (e.g. spironolactone, eplerenone) if bilateral hyperplasia

• Surgery if adenoma