Cushing's syndrome is a disorder caused by the body’s exposure to an excess of the hormone cortisol. Cortisol affects all tissues and organs in the body. These effects together are known as Cushing's syndrome.
Cushing’s syndrome can be caused by overuse of cortisol medication, as seen in the treatment of chronic asthma or rheumatoid arthritis (iatrogenic Cushing’s syndrome), excess production of cortisol from a tumor in the adrenal gland or elsewhere in the body (ectopic Cushing’s syndrome) or a tumor of the pituitary gland secreting adrenocorticotropic hormone (ACTH) which stimulates the overproduction of cortisol from the adrenal gland (Cushing’s disease).
Cortisol is a normal hormone produced in the outer portion of the adrenal glands. When functioning correctly, cortisol helps the body respond to stress and change. It mobilizes nutrients, modifies the body's response to inflammation, stimulates the liver to raise blood sugar and helps control the amount of water in the body. Cortisol production is regulated by the ACTH produced in the pituitary gland.
Prevalence of Cushing’s Syndrome
An estimated 10-15 per million people are affected every year.
Pituitary adenomas (Cushing’s disease) account for more than 70 percent of cases in adults and about 60-70 percent of cases in children and adolescents.
Cushing’s syndrome most commonly affects adults ages 20-50 and is more prevalent in females, accounting for about 70 percent of all cases.
Underlying Causes
Pituitary Adenomas — Cushing’s Disease
Pituitary adenomas are benign tumors of the pituitary gland that secrete increased amounts of ACTH causing excessive cortisol production. Most patients have a single adenoma. First described in 1912 by neurosurgeon Harvey Cushing, MD, in his book The Pituitary Body and Its Disorders, Cushing’s disease is the most common cause of spontaneous Cushing’s syndrome, accounting for 60-70 percent of all cases.
