What condition is characterized by elevated levels of cortisol?

Cushing's Syndrome is characterized by elevated levels of cortisol, which can result from various factors such as adrenal tumors, pituitary tumors producing excess adrenocorticotropic hormone (ACTH), or prolonged use of corticosteroid medications. In this condition, the excessive cortisol leads to a range of manifestations including weight gain, moon facies, thinning of the skin, hypertension, and glucose intolerance.

Addison's Disease, on the other hand, is associated with insufficient cortisol production due to adrenal insufficiency. Hyperthyroidism and Graves' Disease primarily involve the thyroid gland and relate to elevated levels of thyroid hormones rather than cortisol levels. Thus, the unique hallmark of Cushing's Syndrome is the excess of cortisol, which clearly distinguishes it from the other listed conditions.