Cushing's disease, as well as Cushing's syndrome, is caused by the overproduction of something called cortisol. Cortisol is "a normal hormone produced in the outer portion, or cortex, of the adrenal glands" (Margulies). Whether your body naturally overproduces this hormone, or your body receives too much cortisol in steroid medications used as treatment for other diseases, it can lead to development of Cushing's disease. In normal function, cortisol helps the body respond to changes and to stressors. Its normal functions include the mobilization of nutrients, modifying the body's response to inflammation, getting the liver to raise blood sugar levels, and regulating the amount of water in the body (Margulies). Adrenocorticotrophic hormone (ACTH for short) is made by the pituitary gland, and regulates cortisol production. Overproduction of cortisol, or taking in excess amounts via medications causes significant changes in "all of the tissues and organs of the body" (Margulies). The culmination of these changes is what is typically labeled "Cushing's disease" or "Cushing's syndrome"; dependent upon the way the condition has developed. According to the American Academy of Family Physicians, "Cushing's syndrome" is used to describe the condition when it is the direct result of the body's long-term exposure to excessive amounts of cortisol through medications. "Cushing's disease" is used for patients who have the condition because of the excessive production of cortisol by a pituitary tumor. (Kirk, 1119)

According to the American Family Physician magazine, some of the common...

It begins with a physical exam, looking for the common physical characteristics of the illness. If the cause is medicines that are being used to treat other illnesses (asthma, systemic lupus, severe allergies, inflammatory bowel disease, rheumatoid arthritis and others {Margulies}), no further testing is usually required (Kirk, 1134). Urine and blood tests are used to diagnose the disease in those who are not taking any steroid medications. Some patients may need a CT scan or an MRI, which will show any tumors present (Kirk, 1134).
Treatment of Cushing's disease usually involves the removal of the tumor from the pituitary gland, which alone is usually successful. This surgery is usually performed by a neurosurgeon using a procedure called "transsphenoidal resection" which means "behind the nose" (Margulies). Sometimes, the entire pituitary gland is removed, which results in the giving of replacement hormones for those missing - "cortisol,…