Cushing's syndrome is a disorder caused by excessive amounts of the hormone cortisol in the blood. Cortisol is produced by the adrenal glands, which are located just above the kidneys.

Cushing's syndrome can be caused by:

• Long-term use of medication resembling cortisol (corticosteroids).
• A tumor on the pituitary gland in the brain. (The noncancerous tumor causes the pituitary gland to produce too much of the hormone called adrenocorticotropic hormone, or ACTH, which in turn causes the adrenal glands to produce too much cortisol. This condition is called Cushing's disease.)
• A tumor of the adrenal gland.
• Some types of cancer that produce ACTH.

Cushing's syndrome can cause a round, reddish face; pads of fat on the chest and upper back; diabetes; high blood pressure; tendency to bruise easily; fatigue; high blood sugar levels; and emotional changes.

Depending on the cause, Cushing's syndrome is treated with medications, surgery, radiation, or a combination of these.