The production of cortisol by the adrenals is precisely regulated by the brain's hypothalamus and the pituitary gland, a bean-sized organ at the base of the brain. First, the hypothalamus sends releasing hormones to the pituitary gland. When the adrenals receive the pituitary's signal, in the form of ACTH, they respond by producing cortisol as well as some of the other adrenal hormones.
Glucocorticoids affect almost every organ and tissue in the body.
One of cortisol's most important jobs is to help the body respond to stress. In fact, the adrenal glands naturally produce more cortisol during stress. Aldosterone belongs to a class of hormones called mineralocorticoids , which are also produced by the adrenal glands. It helps maintain blood pressure and water and salt balance in the body by helping the kidney retain sodium and excrete potassium. When aldosterone production falls too low, the kidneys are not able to regulate salt and water balance, causing blood volume and blood pressure to drop.