Difference Between Cushing's Syndrome & Cushing's Disease

Cushing's syndrome and Cushing's disease both arise from an excess of corticosteroid hormones in the body. The distinguishing feature between the two has to do with what causes this overproduction. If the specific cause is a pituitary tumor that causes the adrenals to overproduce, it is referred to as Cushing's disease.

Symptoms

• The symptoms of either condition, according to the "Merck Manual of Medical Information," 2d ed. (Whitehouse Station, NJ: Merck Research Laboratories, 2003), pp. 958-59, are sudden excessive fat in the torso, a "moon face," loss of muscles, thin skin, easy bruising and purple streaks over the abdomen.

Identification

• To identify these two conditions, cortisol levels in the blood are measured. Normally these levels fluctuate daily. Continually high levels call for a dexamethasone suppression test to locate the cause.

Considerations

• If a dexamethasone test shows a modest drop in cortisol, the pituitary gland may be over-stimulating the adrenals, suggesting Cushing's disease. If the level stays high, the cause of the syndrome is elsewhere. A significant drop may rule out either condition.

Treatment

• Further tests will be needed to determine the location of the tumor causing the condition. Treatment may require surgery or radiation.

Warning

• According to an article in the "American Family Physician," the most usual cause of Cushing's syndrome is the use of glucocorticoid drugs. These are powerful anti-inflammatory drugs, such as prednisone and hydrocortisone.