Aldosterone is a hormone produced in the adrenal gland and plays an essential role in maintaining normal concentrations of sodium and potassium in the blood and in controlling blood volume and blood pressure. It is often ordered in patients with high blood pressure (especially in case of low potassium) along with the test Renin (angiotensinogenase), which is protein and enzyme secreted by the kidneys, activator of the angiotensin hormone that stimulates aldosterone production: the body's renin–angiotensin–aldosterone system (RAAS)
A variety of conditions can lead to aldosterone overproduction
(hyperaldosteronism, usually just called aldosteronism) or
underproduction (hypoaldosteronism). Since renin and aldosterone are so
closely related, both substances are often tested together to identify
the cause of an abnormal aldosterone. Healthcare practitioners may order the ACTH stimulation tests along with cortisol to determine if someone has Addison disease, low pituitary function, or a pituitary tumor. A normal result is a cortisol increase and an increase in aldosterone after stimulation by ACTH.