[Idiopathic primary hyperaldosteronism: significance of functional diagnosis].

Primary aldosteronism is a rare cause of hypertension caused by increased aldosterone secretion. The two essential stimuli for aldosterone production, potassium and angiotensin II, tend to be low. At a time when imaging procedures are becoming more common, more patients are being found with adrenal masses, and patients with incidentalomas and low renin hypertension could be considered as candidates for surgery. Apart from an appropriate work-up for the diagnosis of primary aldosteronism, the differential diagnosis between unilateral adenoma and idiopathic ("hyperplasia") hyperaldosteronism is relevant for the choice of therapy. Based on data from the literature and four patients we observed as outpatients in 1997, we suggest that a properly conducted and carefully interpreted postural stimulation test can be useful in identifying patients who are successfully treated by drugs.