Cushing's disease is caused by a tumor or excess growth ( hyperplasia ) of the pituitary gland. This gland is located at the base of the brain.

People with Cushing's disease have too much ACTH. ACTH stimulates the production and release of cortisol, a stress hormone. Too much ACTH means too much cortisol.

Cortisol is normally released during stressful situations. It controls the body's use of carbohydrates , fats , and proteins and also helps reduce the immune system's response to swelling (inflammation).

• Abdomen that sticks out and thin arms and legs (central obesity )
• Acne or skin infections
• Collection of fat on the back of the neck (buffalo hump )
• Depression
• Diabetes
• Easy bruising
• Excessive facial hair growth in females
• Headache
• Impotence
• Increased urination
• Moon face (round, red, and full)
• Osteoporosis
• Purple stretch marks on the abdomen, thighs, and breasts
• Stopping of menstruation
• Weakness
• Weight gain

Tests are done to confirm there is too much cortisol in the body, then to determine the cause.

These tests confirm too much cortisol:

• 24-hour urine cortisol
• Dexamethasone suppression test (low dose)

These tests determine cause:

• Brain MRI
• Dexamethasone suppression test (high dose)
• Serum ACTH levels
• Test of corticotropin-releasing hormone, which acts on the pituitary gland to cause the release of ACTH (CRH test)
• Test that measures ACTH levels in the veins that drain the pituitary gland (petrosal sinus sampling)

Treatment involves surgery to remove the pituitary tumor, if possible. After surgery, the pituitary may slowly start to work again and return to normal.

During the recovery process, you may need cortisol replacement treatments. Radiation treatment of the pituitary gland may also be used.

If the tumor does not respond to surgery or radiation, you may get medications to stop your body from making cortisol.

If these treatments are not successful, the adrenal glands may need to be removed to stop the high levels of cortisol from being produced.

Untreated, Cushing's disease can cause severe illness, even death. Removal of the tumor may lead to full recovery, but the tumor can grow back.

• Compression fractures
• Diabetes
• High blood pressure
• Infections
• Kidney stones
• Psychosis

Call your health care provider if you develop symptoms of pituitary Cushing's.

If you have had a pituitary tumor removed, call if you have signs of complications, including signs that the tumor has returned.

5. Stewart PM. The Adrenal Cortex. In: Kronenberg: Willliams Textbook of Endocrinology. Philadelphia, Pa: Saunders Elsevier; 2008:chap 14.