Unilateral adrenal hyperplasia is a usual cause of primary hyperaldosteronism. Results from a Swedish screening study.

Background: The existence of unilateral adrenal hyperplasia (AH) has been considered a rare cause of primary hyperaldosteronism (PA).

Methods: In a prospective study we screened for PA in a non-selected (NSP) and selected hypertensive population (SP), to define the cause of PA. We included 353 consecutive patients with hypertension; age 20 to 88 years, 165 women and 188 men, from a university-based Hypertension and Nephrology Outpatient clinics (123 SP) and two primary care centres, (230 NSP) from the same catch-up area.