Cushing Syndrome

Cushing syndrome is a disorder that occurs when your body has a high level of the hormone cortisol.

The most common cause of Cushing syndrome is taking too much glucocorticosteroid medicine. This form of Cushing syndrome is called exogenous Cushing syndrome. Prednisone, dexamethasone, and prednisolone are examples of this type of medicine. Glucocorticoids mimic the action of the body's natural hormone cortisol. These drugs are used to treat many conditions such as asthma, skin inflammation, cancer, bowel disease, joint pain, and rheumatoid arthritis.

Other people develop Cushing syndrome because their body produces too much cortisol. This hormone is made in the adrenal glands. Causes of too much cortisol are:

• Cushing disease, which occurs when the pituitary gland makes too much of the hormone ACTH. ACTH then signals the adrenal glands to produce too much cortisol. A pituitary gland tumor can cause this condition
• Tumor of the adrenal gland
• Tumor elsewhere in the body that produces corticotropin-releasing hormone (CRH)
• Tumors elsewhere in the body that produce ACTH (ectopic Cushing syndrome)

Cushing Syndrome Symptoms

Symptoms vary. Not everyone with Cushing syndrome has the same symptoms. Some people have many symptoms while others have hardly any symptoms.

Most people with Cushing syndrome have:

• Round, red, full face (moon face)
• Slow growth rate (in children)
• Weight gain with fat accumulation on the trunk, but fat loss from the arms, legs, and buttocks (central obesity)

Skin changes that are often include:

• Skin infections
• Purple marks (1/2 inch or 1 centimeter 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 and above collar bone
• Rib and spine fractures caused by thinning of the bones
• Weak muscles, especially of the hips and shoulders

Women with Cushing syndrome often have:

• Excess hair growth on the face, neck, chest, abdomen, and thighs
• Periods that become irregular or stop

Men may have:

• Decreased or no desire for sex
• Erection problems

Other symptoms that may occur with this disease:

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

Diagnosing Cushing Syndrome

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

• Blood cortisol levels
• Blood sugar
• Saliva cortisol levels
• Dexamethasone suppression test
• 24-hour urine for cortisol and creatinine
• ACTH level
• ACTH stimulation test (rarely)

Tests to determine the cause or complications may include:

• Abdominal CT
• ACTH
• Pituitary MRI
• Bone mineral density

Cushing Syndrome Treatment

Treatment depends on the cause.

Cushing syndrome caused by corticosteroid use:

• Your doctor will instruct you to slowly decrease the medicine dosage. Stopping the medicine suddenly can be dangerous.
• If you cannot stop taking the medicine because of disease, your high blood sugar, high cholesterol levels, and bone thinning or osteoporosis should be closely monitored.

With Cushing syndrome caused by a pituitary or a tumor that releases ACTH (Cushing disease), you may need:

• Surgery to remove the tumor.
• Radiation after removal of a pituitary tumor in some cases.
• Cortisol replacement therapy after surgery and possibly for the rest of your life.

With Cushing syndrome due to an adrenal tumor or other tumors:

• You may need surgery to remove the tumor.
• If the tumor cannot be removed, you may need medicines to help block the release of cortisol.