Cushing's Syndrome Diagnosis and Diagnostic Tests
  • Comprehensive health history and physical examination
  • 24 hour urine collection to assess for free cortisol
    • 50-100 mcg/day of cortisol in urine indicates Cushing's syndrome (Lewis et al., 2007)
    • Levels may be elevated with loss of variation in absence of stress and illness
  • Dexamethasone suppression test (if urine tests are borderline)
  • Plasma ACTH levels
    • Can vary depending on underlying conditions
    • Normal to high levels indicate ACTH-dependent Cushing's disease (Pagana & Pagana, 2010)
    • Adrenal cortex disorders or use of medications can result in a decreased ACTH (ATI, 2010)
  • X-Ray, CT, MRI of pituitary gland, adrenal gland, lungs, GI tract, or pancreas to assess for lesions, tumors, or adrenal atrophy (ATI, 2010)
  • Blood glucose
    • Increased
  • Serum electrolytes
    • Hypokalemia, hypocalcemia, hypernatremia
  • Lymphocytes
    • Decreased