Cushing's syndrome

Causes

Appropriate Tests

 

Dexamethasone suppression test-overnight and/or Cortisol urine are performed initially, as normal results exclude Cushing’s syndrome. Diagnositic but not if on estrogens or medication for metabolism.

Free cortisol (24 h urine free cortiol, midnight  salivary contol).

Salivary cortisol.

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

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)