Primary aldosteronism (PA) is the most common form of secondary arterial hypertension. In patients with PA, more so than in the general population, there is a prevalence of insulin resistance, diabetes mellitus, metabolic syndrome, osteoporosis, and symptoms of depression; these conditions are more likely to manifest a gluco- rather than mineralocorticoid excess. This fact is of particular importance in light of recent studies that have shown that PA is often associated with glucocorticoid excess. Since the first reports of cases of combined secretion of aldosterone and cortisol in 1979, the number of cases of so-called Connshing syndrome has increased. An analysis of data from recent studies suggests that hypercortisolism in PA is closely associated with an increased risk of cardiovascular complications, metabolic disorders and post-surgical adrenal insufficiency. The most important diagnostic problem in adenomas with combined secretion is the risk of false interpretation of the results of adrenal venous sampling (AVS). The indications that suggest aldosterone-and-cortisol-co-producing adenoma are the lack of suppression of cortisol levels following a night test with 1mg of dexamethasone, and an adrenal tumo of over 2.5cm. As an alternative test capable of differentiating this type of tumor, a number of researchers have proposed measuring the level of so-called hybrid steroids in the peripheral plasma and urine. Taking into account the high prevalence and potential risks, ruling out of excess corisol secretion is obligatory in all cases of PA before AVS and when planning surgery.