What is Cushing's Syndrome?

Cushing's Syndrome is a condition caused by prolonged exposure to too much cortisol. It can be from a tumor (pituitary, adrenal, or lung) or from taking steroid medications.

Classic Signs ("Cushingoid Features"):

• Moon Face: Round, puffy face.
• Buffalo Hump: Fat deposit on the upper back/neck.
• Central Obesity: Large belly, thin arms/legs.
• Purple Striae: Wide, purple stretch marks on the abdomen.
• Easy Bruising & Thin Skin.
• Proximal Muscle Weakness: Difficulty standing from a squat.
• High Blood Pressure & High Blood Sugar.

Causes:

• Exogenous (Most Common): Taking prescription steroids (Prednisone, Dexamethasone).
• Cushing's Disease: Pituitary tumor making too much ACTH.
• Adrenal Tumor: Making cortisol directly.
• Ectopic ACTH: Lung cancer or other tumors secreting ACTH.

Diagnosis:

• 24-Hour Urine Free Cortisol: Measures total cortisol output.
• Late-Night Salivary Cortisol: Cortisol should be low at night; in Cushing's, it stays high.
• Low-Dose Dexamethasone Suppression Test: In healthy people, taking dexamethasone shuts off cortisol; in Cushing's, it doesn't.

Treatment:

Depends on the cause. Surgery to remove the tumor (pituitary or adrenal) is the goal. Medications like Ketoconazole or Metyrapone can block cortisol production.