Primary hyperaldosteronism

Physiology · Endocrine physiology

Primary hyperaldosteronism was previously thought to be most commonly caused by an adrenal adenoma, termed Conn's syndrome. However, recent studies have shown that bilateral idiopathic adrenal hyperplasia is the cause in up to 70% of cases. Differentiating between the two is important as this determines treatment. Adrenal carcinoma is an extremely rare cause of primary hyperaldosteronism.

Features

hypertension
hypokalaemia (e.g. muscle weakness)
alkalosis

Investigations (in addition to above)

high serum aldosterone
low serum renin
high-resolution CT abdomen
adrenal vein sampling

Management

adrenal adenoma: surgery
bilateral adrenocortical hyperplasia: aldosterone antagonist e.g. spironolactone


© Image used on license from Radiopaedia

CT abdomen showing a right-sided adrenal adenoma in a patient who presented with hypertension and hypokalaemia. The adenoma can be seen 'next to' or 'below' the liver.