Primary aldosteronism (PA), characterized by the inappropriate and abnormal adrenal secretion of aldosterone, is the most common cause of secondary hypertension. PA has been shown to increase cardiovasular and cerebrovascular risks in comparison with essential hypertension. PA is a multi-faceted disease, which comprises unilateral forms, benefitting from surgical treatment, and bilateral forms, which are the best managed medically. PA is more frequently sporadic, but in some cases, it displays a familial transmission pattern. For these reasons, it is important to diagnose PA early on and correctly distinguish and manage its different forms. In this review, we analyze the different forms of PA, with attention on the diagnostic pathway and the genetics of the disease.