Primary aldosteronism (PA) is the most common endocrine cause of hypertension that affects ~5-10% of hypertensive patients in the community. Current recommendations for screening may lead to missed opportunity for diagnosis based on emerging evidence from studies in primary care. Following screening with the aldosterone to renin ratio, the interpretation of confirmatory test results needs to consider aldosterone assay characteristics as well as sample handling and storage. The classification of PA as unilateral or bilateral subtypes is based on adrenal imaging and adrenal vein sampling. The success of adrenal vein cannulation and the degree of lateralisation of aldosterone excess can be significantly affected by intra-procedural sedation and ACTH stimulation. In patients with unilateral disease who undergo adrenalectomy, their adrenal histopathology is no longer the simple distinction between adenoma and hyperplasia. CYP11B2 staining is a new player with an impact on clinical outcomes.