Cushing's Syndrome
Definition
Cushing's syndrome is a hormonal disorder. It is caused by prolonged exposure to the hormone cortisol.
Hormones are chemicals in the body. Cortisol is a common hormone. In normal doses it helps the body manage stress and infection.
Causes
Prolonged or excess exposure to cortisol as a result of:
- Long-term use of corticosteroid hormones such as cortisone or prednisone
- Tumor or abnormality of the adrenal gland, which causes the body to produce excess cortisol
- Tumor or abnormality of the pituitary gland, which causes the body to produce excess cortisol (in the case of a pituitary tumor, it is called Cushing's disease)
- Rarely, tumors of the lungs, thyroid, kidney, pancreas, or thymus gland produce hormones that trigger the syndrome
Pituitary and Adrenal Glands
Risk Factors
Factors that increase your risk of Cushing's syndrome include:
- Chronic use of corticosteroid medicines
- Age: 20-50 years
- Sex: female (much more common in women)
Symptoms
Although symptoms may vary, common symptoms of Cushing's syndrome are:
- Weight gain of the upper body and trunk
- Face shaped like a moon
-
Skin changes:
- Darkening of the skin
- Purple stretch marks
- Easy bruising
- Excess hair growth or acne in women
- Menstrual disorders, especially infrequent or absent periods
- Diminished fertility and libido
- High blood pressure
- Water retention or swelling
- High blood sugar or diabetes
- Tiredness or fatigue
- Personality changes or mood swings
- Muscle weakness
- Osteoporosis or brittle bones
- Skeletal delayed growth in children
- Increased thirst
- Frequent urination
- Psychosis
- Low back pain
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done.
Tests for Cortisol Levels
- 24-hour urinary free cortisol level—Urine is collected for 24 hours and tested.
- Late-evening cortisol saliva/blood level—Saliva or blood is collected around 11 pm and tested.
- Dexamethasone suppression test—A synthetic cortisol called dexamethasone is taken by mouth; blood and urine samples may be taken overnight or over several days.
Tests to Determine Cause of Cushing's Syndrome
- CRH stimulation test
- ACTH level
- High-dose dexamethasone suppression test
X-rays and Scans
These tests may show whether there is a tumor in the pituitary or adrenal glands or another area of the body. Common imaging tools include:
- MRI scan —a test that uses magnetic waves to make pictures of the inside of the body
- CT scan —a type of x-ray that uses a computer to make pictures of structures inside the body
- Chest x-ray —which may detect tumors in the lungs
Treatment
Treatment of Cushing's syndrome depends on the cause.
Treatments include:
- Surgical removal of tumor
- Surgical removal of part, all, or both adrenal glands
- Radiation for some persistent tumors
- Gradual withdrawal of cortisone-type drugs under close medical supervision
- Drugs that decrease cortisol production or block the functioning of other adrenal products
Prevention
Work with your doctor to keep use of corticosteroid drugs to a minimum.
Resources:
American Academy of Family Physicians
Cushing's Support and Research Foundation
Canadian Resources:
Canadian Family Physician
Health Canada
References:
Arnaldi G, Angeli A, Atkinson AB, Bertagna X, et al. Diagnosis and complications of Cushing’s syndrome: a consensus statement. J Clin Endocrinolo Metabo. 2003;88:5593-5602.
Cushing's Syndrome. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: http://www.niddk.nih.gov/health/endo/pubs/cu...ngs/cushings.htm. Updated July 2008. Accessed July 8, 2009.
Diez JJ, Iglesias P. Pharmacological therapy of Cushing’s syndrome: drugs and indications. Mini Rev Med Chem. 2007;7(5):467-480.
Fauci AS, Braunwald E, Isselbacher KJ, et al. Harrison's Principles of Internal Medicine. 14th ed. New York, NY: The McGraw-Hill Companies; 2000.
Kirk LF Jr, Hash RB, Katner HP, Jones T. Cushing's disease: clinical manifestations and diagnostic evaluation. Am Fam Physician. 2000;62(5):1119-1127, 1133-1134.
Makras P, Toloumis G, Papadoglas D, et al. The diagnosis and differential diagnosis of endogenous Cushing’s syndrome. Hormones. 2006;5:231-250.
Yaneva M, Mosnier-Pudar H, Dugue MA, et al. Midnight salivary cortisol for the initial diagnosis of Cushing’s syndrome of various causes. J Clin Endocrinol Metab. 2004;89(7):3345-3351.
Last reviewed September 2010 by B. Gabriel Smolarz, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.