Final answer:
The diagnostic workup for Cushing's includes testing cortisol levels through urine, saliva, or blood. A high dose dexamethasone suppression test is used to identify the hypercortisolism source; suppression suggests an ectopic source. Treatment is aimed at reducing cortisol levels through various methods.
Step-by-step explanation:
The diagnostic workup of Cushing's syndrome includes measurement of urine, saliva, or blood to measure cortisol levels. When hypercortisolism is determined, a high dose dexamethasone suppression test is done to determine the source of increased cortisol production. If cortisol production is suppressed by the high dose of dexamethasone, then the source of the hypercortisolism is likely to be an ectopic source rather than a pituitary adenoma (which would not suppress with high dose dexamethasone). Hypersecretion of the hormone cortisol leads to Cushing's syndrome, often caused by a pituitary tumor which overproduces ACTH. Treatments are focused on reducing the excessive cortisol levels, which may include surgery, radiation therapy, or medications.