the clinical spectrum and knowledge of the molecular mechanisms underlying primary aldosteronism (PA), the most frequent form of endocrine hypertension, has evolved over the past years. In accordance with the Endocrine Society guideline and in light of the growing evidence showing adverse cardiovascular outcomes, it is expected that a progressively wider population of patients affected by hypertension will be screened for PA, including the elderly.a systematic search of PubMed was undertaken for studies related to renin-angiotensin-aldosterone system (RAAS), primary aldosteronism and adrenal histopathology in the elderly population.several studies showed an age-dependent decrease in the activity of RAAS, together with a progressive decrease of the aldosterone response to sodium intake, particularly after the sixth decade of life. The positive correlation between age and serum aldosterone during liberal sodium intake over serum aldosterone during sodium restriction is paralleled by histological changes in adrenal aldosterone synthase (CYP11B2) expression patterns. Immunohistochemical studies showed a progressive loss of the continuous expression of CYP11B2 in adrenal zona glomerulosa with ageing and a concomitant increase of aldosterone-producing cell clusters, which might be responsible for a relatively autonomous aldosterone production. Additionally, following PA confirmation and subtype diagnosis, older age is correlated with a lower benefit after adrenalectomy for unilateral PA.accumulating evidence suggests that RAAS physiology and regulation show age-related changes. Further studies may investigate to what extent these variations might affect the diagnostic work-up of patients affected by PA.