Cushing syndrome: MedlinePlus Mobile Medical Encyclopedia

Cushing syndrome is a disorder that occurs when your body is exposed to high levels of the hormone cortisol. It may also occur if you take too much cortisol or other steroid hormones.

See also: Cushing's disease (pituitary Cushing's)

Causes
Cushing syndrome may be caused by taking too much corticosteroid medications, such as prednisone and prednisolone. These drugs are used to treat conditions such as asthma and rheumatoid arthritis.

Other people develop Cushing syndrome because their bodies produce too much cortisol, a hormone normally made in the adrenal gland. Causes of too much cortisol are:

Cushing's disease, when the pituitary gland makes too much of the hormone ACTH. ACTH then signals the adrenal glands to produce cortisol. Tumor of the pituitary gland may cause this condition.
Tumor of the adrenal gland
Tumor elsewhere in the body that produces cortisol
Tumors elsewhere in the body that produce ACTH (such as the pancreas, lung, and thyroid)

Symptoms
Most people with Cushing syndrome will have:

Upper body obesity (above the waist) and thin arms and legs
Round, red, full face (moon face)
Slow growth rate in children

Skin changes that are often seen:

Acne or skin infections
Purple marks (1/2 inch or more wide) called striae on the skin of the abdomen, thighs, and breasts
Thin skin with easy bruising

Muscle and bone changes include:

Backache, which occurs with routine activities
Bone pain or tenderness
Collection of fat between the shoulders (buffalo hump)
Rib and spine fractures (caused by thinning of the bones)
Weak muscles

Women with Cushing syndrome often have:

Excess hair growth on the face, neck, chest, abdomen, and thighs
Menstrual cycle that becomes irregular or stops

Men may have:

Decreased or no desire for sex
Impotence

Other symptoms that may occur with this disease:

Mental changes, such as depression, anxiety, or changes in behavior
Fatigue
Headache
Increased thirst and urination

Exams and Tests
Blood sugar and white blood cell counts may be high. Potassium level may be low.

Laboratory tests that may be done to diagnose Cushing syndrome and identify the cause are:

Serum cortisol levels
Salivary cortisol levels
Dexamethasone suppression test
24-hour urine for cortisol and creatinine
ACTH level
ACTH (cosyntropin) stimulation test

Tests to determine the cause or complications may include:

Abdominal CT
ACTH test
Pituitary MRI
Bone density, as measured by dual x-ray absorptiometry (DEXA)

High cholesterol, including high triglycerides and low high-density lipoprotein (HDL) may also be present.

Treatment
Treatment depends on the cause.

Cushing syndrome caused by corticosteroid use:

Slowly decrease the drug dose (if possible) under medical supervision.
If you cannot stop taking the medication because of disease, your high blood sugar, high cholesterol levels, and bone thinning or osteoporosis should be closely monitored.

Cushing syndrome caused by a pituitary or a tumor that releases ACTH (Cushing's disease):

Surgery to remove the tumor
Radiation after removal of a pituitary tumor (in some cases)
You may need hydrocortisone (cortisol) replacement therapy after surgery, and possibly continued throughout your life

Cushing syndrome due to an adrenal tumor or other tumors:

Surgery to remove the tumor
If the tumor cannot be removed, medications to help block the release of cortisol

Outlook (Prognosis)
Removing the tumor may lead to full recovery, but there is a chance that the condition will return.

Survival for people with ectopic tumors depends on the tumor type. Untreated, Cushing syndrome can be life-threatening.

When to Contact a Medical Professional
Call your health care provider if you have symptoms of Cushing syndrome.

Alternative Names
Hypercortisolism

References
Stewart PM, Krone NP. The adrenal cortex. In: Kronenberg HM, Shlomo M, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology . 12th ed. Philadelphia, Pa: Saunders Elsevier;2011:chap 15.

Update Date: 12/11/2011
Nancy J. Rennart, MD, Chief of Endocrinology & Diabetes, Norwalk Hospital, Associate Clinical Professor of Medicine, Yale University School of Medicine. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.