Cushing's syndrome

Last updated: Wednesday, 24, November, 2010
CausesAppropriate Tests

Dexamethasone suppression test (overnight) and/or cortisol (free) - urine are performed initially, as normal results exclude Cushing’s syndrome.

In patients with abnormal results, a dexamethasone suppression test (long), including ACTH levels, provides the definitive diagnosis and differentiates pituitary from adrenal causes. Electrolytes.

Diagnostic imaging, as appropriate.

Cushing's disease

Pituitary-dependent adrenal hyperplasia. See Pituitary hormone excess-Adrenocorticotrophin excess
  • Corticotroph adenoma

Adrenal adenoma/carcinoma

Ectopic ACTH syndrome

Iatrogenic (corticosteroid therapy)