Cortisol isn’t bad; you need it to help regulate your responses to life. Regulation involves a very complex interplay of feedback loops between the hypothalamus, pituitary gland, and adrenal glands, says Dr. Singh.

“In general, cortisol levels tend to peak in the late morning and gradually decline throughout the day,” he explains. “When a stressful event occurs, the increased cortisol will work alongside our ‘fight or flight’ mechanisms to either upregulate or downregulate bodily functions. [Affected systems include] the central nervous system, cardiovascular system, gastrointestinal system, or immune system.”

In addition to normal processes that trigger or suppress cortisol release, levels can also be affected by different medical conditions, Dr. Singh says. For example, if someone has abnormally high levels of cortisol, this is called Cushing’s syndrome, which is typically caused by a tumor affecting any of the glands that take part in the process of cortisol production.

When people suffer from abnormally low levels of cortisol, it’s called Addison’s disease. It generally occurs due to adrenal gland dysfunction, but could also be the result of abnormal functioning of any of the other glands in the cortisol production process.

Finally, if you use corticosteroid medications such as prednisone or dexamethasone, prolonged use will result in excessive cortisol production, Dr. Singh says.

“If the medication is not adequately tapered down when discontinued, the body’s ability to create cortisol can become permanently impaired,” he says.

From https://www.yahoo.com/lifestyle/manage-pesky-stress-hormone-cortisol-184900397.html