Hello and welcome to this short series of posts on Cushing's Syndrome/Disease! The series is divided into five posts, each with its own topic. So without further ado, let's jump right in.
Before discussing Cushing's, we must first discuss cortisol. Cortisol is a glucocorticoid (steroid) hormone which plays an important role in glucose and fat metabolism and reducing inflammation. The hormone is also referred to as the "stress" or "flight-or-fight" hormone, as it, along with epinephrine (adrenaline) is released during "flight-or-fight" situations.
The hypothalamus, at the base of the brain, secretes CRH (corticotropin-releasing-hormone), which signals the pituitary gland to secrete ACTH, which in turn signals the adrenal glands to start producing cortisol. This pathway has a negative feedback loop, meaning that, under normal circumstances, if there is too much cortisol in the body, CRH production will stop, causing ACTH production to stop, which in turn causes cortisol production to stop until levels normalize. In Cushing's disease, this negative loop does not work, causing a buildup of excess cortisol (but more on that next time!).
Glucocorticoids, such as cortisol, are used for a variety of medical purposes. Hydrocortisone (another name for cortisol) is used in creams to alleviate the symptoms of hemorrhoids and other diseases. Prednisone is used to relieve swelling in asthma patients. Nasonex is another glucocorticoid, with the the generic name mometasone. Taking any of these medications in excess or for a prolonged time could lead to excess cortisol in the bloodstream (see the next post for details).Next post, we will discuss the effects of high cortisol in the bloodstream and the difference between Cushing's Disease and Cushing's Syndrome.