While cortisol helps the body deal with extreme stress, aldosterone continually regulates the balance of salt and water. Though both hormones are released by the adrenal glands, they have very different responsibilities. Cortisol kicks in when there is a perceived threat. Aldosterone is produced on a regular basis.
Cortisol reacts with other hormones, such as adrenaline, to prepare the body for a fight-or-flight situation. It increases the amount of glucose that is available in the bloodstream and makes it easier for the brain to use glucose.
Cortisol also gets the body ready to deal with injury by boosting the amount of substances that may be needed for repair. In the face of a threat, cortisol signals non-essential services, such as the reproductive and digestive systems, to slow down. Growth is also suppressed.
Chronic production of cortisol, the result of long-term stress, results in digestive problems, heart disease, anxiety and depression. Aldosterone reacts to the body's needs. In general, its job is to retain a healthy amount of sodium and water in the blood while making the kidneys excrete potassium in the urine. A tumor in the adrenal gland can upset this process, contributing to high blood pressure or low blood potassium levels.