Cushing syndrome is a disorder that occurs when your body has a high level of the hormone cortisol.
Hypercortisolism; Cortisol excess; Glucocorticoid excess - Cushing syndrome
The most common cause of Cushing syndrome is taking too much glucocorticoid or corticosteroid 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)
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 can include:
- Skin infections
- Purple stretch marks (1/2 inch or 1 centimeter or more wide) called striae on the skin of the abdomen, upper arms, thighs, and breasts
- Thin skin with easy bruising (especially on the arms and hands)
Muscle and bone changes include:
- Backache, which occurs with routine activities
- Bone pain or tenderness
- Collection of fat between the shoulders and above collar bones
- Rib and spine fractures caused by thinning of the bones
- Weak muscles, especially of the hips and shoulders
Body-wide (systemic) changes include:
- Type 2 diabetes mellitus
- High blood pressure (hypertension)
- Increased cholesterol and triglycerides (hyperlipidemia)
Women with Cushing syndrome may 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 (low libido)
- Erection problems
Other symptoms that may occur with this disease:
- Mental changes, such as depression, anxiety, or changes in behavior
- Increased thirst and urination
Exams and Tests
The health care provider will perform a physical exam and ask about your symptoms and the medicines you are taking. Tell the provider about all medicines you have been taking for the past several months. Also tell the provider about shots that you received at a provider's office.
Laboratory tests that may be done to diagnose Cushing syndrome and identify the cause are:
- Blood cortisol level
- Blood sugar
- Saliva cortisol level
- 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:
Treatment depends on the cause.
Cushing syndrome caused by corticosteroid use:
- Your provider 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
- Medicines to replace pituitary hormones that become deficient
- Medicines to prevent the body from making too much cortisol
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.
Removing the tumor may lead to full recovery, but there is a chance that the condition will return.
Survival for people with Cushing syndrome caused by tumors depends on the tumor type.
Untreated, Cushing syndrome can be life threatening.
Health problems that may result from Cushing syndrome include any of the following:
- Enlargement of pituitary tumor
- Fractures due to osteoporosis
- High blood pressure
- Kidney stones
- Serious infections
When to Contact a Medical Professional
Call your provider if you have symptoms of Cushing syndrome.
If you take a corticosteroid, know the signs and symptoms of Cushing syndrome. Getting treated early can help prevent any long-term effects of Cushing syndrome. If you use inhaled steroids, you can decrease your exposure to the steroids by using a spacer and by rinsing your mouth after breathing in the steroids.
Nieman LK, Biller BM, Findling JW, et al; Endocrine Society. Treatment of Cushing's syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2015;100(8):2807-2831. PMID: 26222757 www.ncbi.nlm.nih.gov/pubmed/26222757.
Stewart PM, Newell-Price JDC. The adrenal cortex. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 13th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 15.
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.