Once the diagnosis of hypertension is established, secondary forms should be considered. Especially hormonally active adrenal tumors may allow specific treatment. For primary hyperaldosteronism plasma aldosterone to active renin concentration ratio in patients with plasma aldosterone levels > or = 200 ng/l is a reliable screening method under random conditions. A salt loading test may confirm a primary aldosteronism. A unilateral adrenal adenoma has to be separated from bilateral adrenal hyperplasia. To exclude Cushing's syndrome, the dexamethasone challenge is a reliable screening parameter. Patients with Cushing's syndrome may have an elevated urinary free cortisol and the circadian rhythm may be abolished resulting in an elevated 23:00 h serum cortisol. Alternatively, cortisol may be measured in saliva using specific cutoffs. Determinations of 24-h urinary epinephrine and norepinephrine levels are established diagnostic tools for the diagnosis of pheochromocytoma. Metanephrines, which are metabolites of catecholamines, have been suggested as an alternative more sensitive and specific diagnostic tool. In conclusion, recently established biochemical methods are reliable screening parameters for the diagnosis of adrenal hypertension. Endocrine hypertension due to adrenal tumors may be treated by minimally invasive surgery or specific antihypertensive treatment.