Primary aldosteronism (PA) is the most common cause of mineralocorticoid hypertension. Different studies, using the plasma aldosterone concentration to plasma renin activity ratio (PAC/PRA) for the screening of patients with hypertension, have shown a marked increase in the detection rate of PA. Idiopathic bilateral adrenal hyperplasia (IHA) and aldosterone-producing adrenal adenoma (APA), are the leading causes of primary aldosteronism. Glucocorticoid-remediable aldosteronism (GRA), also called familial hyperaldosteronism type I, familial hyperaldosteronism type II and carcinomas are rare causes of PA. Patients with hypertension and hypokalemia, those with a family history of hypertension and stroke at an early age, or patients with medication-resistant hypertension should be screened for PA using the PAC/PRA ratio. If a high ratio is found, a sodium loading test or a captopril test is warranted to confirm the diagnosis. Adrenal gland imaging is important in subtype differentiation (APA vs IHA). Adrenal venous sampling should be used when other tests prove inconclusive. Genetic testing has facilitated detection of GRA. Surgery is considered the treatment of choice for patients with APA, while bilateral hyperplasia subtypes are treated medically. Normalization of aldosterone levels or aldosterone receptor blockade are necessary to prevent the morbidity and mortality associated with hypertension, hypokalemia, and cardiovascular damage.