What is Cushing's syndrome?
Cushing's syndrome is a rare hormonal problem. It happens when there is too much of the hormone cortisol in your body.
Normally, cortisol levels increase through a chain reaction of hormones:
- First, the brain makes a hormone called CRH (corticotropin-releasing hormone).
- Then, CRH tells the pituitary gland to make another hormone called ACTH (adrenocorticotropic hormone).
- ACTH then tells the adrenal glands to make cortisol. Cortisol affects almost every area of the body. It is especially important in regulating blood pressure and metabolism.
But if your body makes too much cortisol—or if you take certain medicines that act like cortisol—you may start to have symptoms. Cushing's syndrome may cause weight gain, skin changes, and fatigue. It can lead to serious problems, such as diabetes, high blood pressure, depression, and osteoporosis. If not treated, it can also cause death.
Another name for Cushing’s syndrome is hypercortisolism.
What causes Cushing's syndrome?
Cushing's syndrome may be caused by:
- Steroid medicine. This medicine is used to treat lupus, asthma, rheumatoid arthritis, and other diseases that cause inflammation. It may also be used after an organ transplant. Long-term use of this medicine is the most common cause of Cushing's syndrome.
- Tumors on the pituitary gland. This is called Cushing's disease. It’s the second most common cause of Cushing's syndrome. These tumors are not cancer.
- Tumors on the adrenal glands, or in the lung or pancreas. Sometimes these tumors are cancer.
What are the symptoms?
Weight gain—especially around the waist—is the most common symptom.
Cortisol affects almost all body systems, so it can cause many other symptoms. These other symptoms often appear slowly over time and may include:
- Weak muscles.
- Changes in the skin, such as bruising, acne, and dark purple-red stretch marks on the belly.
- Changes in mood. You may feel irritable, anxious, or depressed.
- Extra fat on the back of the neck and upper back.
- Loss of muscle tone.
- Irregular menstrual periods.
- Hair growth that is not normal (such as facial hair in women).
- High blood pressure and high blood sugar levels.
Sometimes alcoholism, depression, panic attacks, obesity, or other problems can cause symptoms like these. Some treatments for HIV can also cause similar symptoms. This is called pseudo-Cushing's syndrome. In these cases, symptoms tend to stop as soon as the problems are treated.
How is Cushing's syndrome diagnosed?
Your doctor will use your medical history, a physical exam, and lab tests to see if you have Cushing's syndrome. During the physical exam, he or she will look for signs of the problem. The medical history includes questions about your symptoms, what medicines you take, and—if you are a woman—whether your periods are regular.
If your doctor thinks you may have Cushing's syndrome, you will have lab tests to check your cortisol levels. These tests can measure cortisol in your blood, urine or saliva. More tests may be needed to find the cause of high cortisol levels.
How is it treated?
Cushing’s syndrome can often be cured. But it can lead to serious health problems, including death. So it’s important to start treatment right away.
If steroid medicine is causing Cushing's syndrome, your doctor will help you lower your dose or gradually stop taking it. It may take a while for the symptoms to go away.
It’s very dangerous to stop taking steroid medicine on your own. Your doctor will help you change your medicine or lower your dose slowly.
If a tumor is causing Cushing’s syndrome, you will need surgery to remove it. If surgery doesn't work, radiation or drugs may be used.
When you have Cushing’s syndrome, it’s very important to control your weight and keep your bones and muscles strong. This will help prevent diabetes, bone loss, and high blood pressure. Eating healthy foods and staying active can help you do this.
It’s also important to have regular checkups to look for other problems such as diabetes, high blood pressure, and osteoporosis.
Frequently Asked Questions
Learning about Cushing's syndrome:
Living with Cushing's syndrome:
The signs and symptoms of Cushing's syndrome vary and most often develop gradually. You may have:
- Weight gain. Symptoms may include a round or puffy face (moon face), increased fat around the neck and upper part of the back (buffalo hump), or an enlarged waistline. Weight gain is the most common symptom of Cushing's syndrome.
- Skin changes. These include thin, fragile skin that bruises easily; slow-healing wounds; wide, purplish stretch marks on the body (striae); acne; or a ruddy complexion.
- Changes in mental state. Irritability, anxiety, inability to sleep (insomnia), or feelings of sadness or depression may develop.
- Muscle and bone weakness. Symptoms may include backache; broken bones, especially the ribs and spine (caused by osteoporosis); or loss of muscle tone and strength. Weakness of the muscles in the arms and legs may make it difficult to rise from a chair or climb stairs.
- Sex hormone changes. Menstrual irregularity, facial hair growth in women, erection problems (erectile dysfunction), or loss of sex drive may occur.
- High blood pressure and diabetes. High blood pressure (hypertension) and diabetes may not be diagnosed until you have a checkup.
The eye conditions glaucoma and cataracts also may develop in Cushing's syndrome. In Cushing's disease (tumors on the pituitary gland), your field of vision can be affected. You may have loss of side, or peripheral, vision.
If a cancerous tumor on the lung is the cause, you may have rapid loss of appetite (anorexia) and weight loss. You also may develop dark spots on the skin (hyperpigmentation).
Not everyone who has the classic signs and symptoms of Cushing's syndrome has the disorder. Also, not everyone who has Cushing's syndrome has the classic changes in physical appearance. This is often true in people who are very physically active.
Exams and Tests
Cushing's syndrome can be difficult to diagnose because a variety of factors—from the time of day to a temporary illness—can lead to a higher-than-average cortisol level in people who do not have Cushing's syndrome. It also can be difficult to pinpoint the cause. This is important because treatment depends on the cause. You may need to see an endocrinologist (a doctor who specializes in hormone disorders) to diagnose or treat Cushing's syndrome.
To diagnose Cushing's syndrome, your doctor will ask about your medical history and do a physical examination. He or she can usually determine from these exams whether corticosteroid medicine is causing the condition. If it is, other tests usually are not done and your doctor will consider changing your medicine.
If you are not taking steroid medicine or your doctor believes something other than steroid medicine is causing Cushing's syndrome, you will have laboratory tests to check your level of cortisol. These tests include:
- A cortisol test, which may be done on a sample of blood or on a sample of urine collected over a 24-hour period.
- An overnight dexamethasone suppression test using a low dose of steroid (often done to reconfirm a cortisol test). This test is most commonly done on a sample of blood, but a more extensive form of the test may involve both blood and urine samples.
Less commonly, a test to measure cortisol in the saliva may be done.
If the above tests show you have Cushing's syndrome, the following blood tests can help your doctor determine the amount of adrenocorticotropic hormone (ACTH) in your body and whether you have a tumor on the adrenal glands, the pituitary gland, or an organ:
If the first tests indicate that too much ACTH is causing Cushing's syndrome, other tests may be needed to determine its source. These include:
- Inferior petrosal sinus sampling (IPSS) to find out whether too much ACTH is being released from the pituitary gland. During IPSS, a small tube (catheter) is used to collect samples from blood vessels near the brain. If these blood samples show high levels of ACTH, it usually indicates that the pituitary gland is the source of excess ACTH. The IPSS is often used with the CRH stimulation test.
- Computed tomography (CT scan) and magnetic resonance imaging (MRI) of the chest or pituitary gland, which may help locate a tumor producing ACTH. But sometimes the tumor may be too small to detect with a CT scan or an MRI. A CT and MRI of the adrenal gland may also be used to locate adrenal tumors.
Blood test results showing changes in body chemistry also may point to Cushing's syndrome. These include:
- An increase in the number of white blood cells (leukocytosis).
- A low potassium level (hypokalemia).
- High blood sugar (hyperglycemia).
- Increased levels of cholesterol (hypercholesterolemia) and high blood fats (hypertriglyceridemia).
- A decrease in the time it takes for blood to clot.
- A high testosterone level.
Treatment for Cushing's syndrome depends on the cause.
For Cushing's syndrome caused by long-term corticosteroid medicine use
Never stop taking corticosteroid medicine on your own because it might lead to a life-threatening adrenal crisis. When you take steroids, your adrenal glands stop making cortisol. If you suddenly stop taking your medicine, your adrenal glands may not be able to start making cortisol quickly enough. This can lead to an adrenal crisis and a severe drop in blood pressure. To avoid this, your doctor will want to gradually reduce and then stop your medicine.
Your doctor may change your corticosteroid medicine from a longer-acting steroid (such as prednisone) to a shorter-acting one (such as hydrocortisone). Sometimes corticosteroid medicines can be taken every other day. Either way, the body's normal production of cortisol returns gradually.
If you must continue taking corticosteroid medicine to control another condition, the dosage can sometimes be lowered to reduce symptoms and the risk of complications.
If your doctor and you are trying to reduce the dosage of your medicine and you become ill, contact your doctor immediately.
If reducing the dosage does not make Cushing's syndrome go away, your doctor will perform more tests to look for another cause of your condition.
For Cushing's syndrome caused by pituitary tumors (Cushing's disease)
If you are well enough to have surgery, surgical removal of the pituitary tumor offers the best chance for recovery. The surgery (transsphenoidal adenomectomy) requires great skill and should be performed at a major medical center where teams of doctors specialize in pituitary surgery.
Transsphenoidal adenomectomy is successful:1
- About 85% of the time if the tumor is less than 0.4 in. (1 cm) in diameter.
- About 25% of the time if the tumor is 0.4 in. (1 cm) in diameter or larger.
Cushing's disease returns in about 2% of adults and up to 40% of children who have the operation.2 Surgery can be repeated, often with good results.
Gamma knife radiosurgery has recently been introduced in the United States. In this technique, many small beams of radiation are focused on the tumor to shrink and destroy it. It does not involve a surgical incision (there is no "knife" involved), and there is minimal damage to surrounding tissue. It can be done as an outpatient and with local anesthesia. Few centers in the United States have gamma knife facilities.
Medicine therapies may be tried if surgery is not possible or has failed.
For Cushing's syndrome caused by adrenal tumors
Doctors almost always recommend surgery to remove benign adrenal tumors that are producing hormones. If a tumor is cancerous, the affected adrenal gland is removed. Although chemotherapy is usually advised, there is no proven long-term treatment for adrenal cancer. On rare occasions, both adrenal glands must be removed. In this case, you would take daily long-term hormone replacement.
Surgery is usually successful if the tumor is not cancerous. But surgery is not as successful for a cancerous tumor if the cancer has spread to other parts of the body.2
If surgery is not possible, medicine therapy may be tried to reduce the tumor's production of cortisol. This includes using ketoconazole (Nizoral), mitotane (Lysodren), and aminoglutethimide (Cytadren). These medicines also are sometimes used before surgery in people with severe Cushing's syndrome. Pregnant women with Cushing's disease can take aminoglutethimide.
For Cushing's syndrome caused by tumors of the lungs and elsewhere
To successfully treat Cushing's syndrome caused by a noncancerous (benign) or cancerous tumor, the tumor tissue that is secreting adrenocorticotropic hormone (ACTH) must be destroyed or removed. Surgery, chemotherapy, radiation therapy, immunotherapy, or a combination of treatments may be recommended to treat the tumor.
If left untreated for a long time, Cushing's syndrome may cause serious problems, including complications from high blood pressure (such as a heart attack or stroke), osteoporosis, or diabetes. The condition also can cause death. Because of these risks, treatment usually begins as soon as possible.
Home treatment for Cushing's syndrome consists of lifestyle changes to prevent weight gain, strengthen muscles and bones, and prevent complications.
- Eat a low-calorie, nutritious diet high in protein and calcium. This can help prevent muscle and bone loss caused by the high cortisol levels in your body. Take calcium and vitamin D supplements to decrease bone loss. Ask your doctor whether you need medicine to help slow bone loss. For more information, see the topic Healthy Eating.
- Limit salt (sodium) in your diet. This is especially important if you have high blood pressure, a complication of Cushing's syndrome.
- Get regular exercise to help maintain muscles and bone mass and prevent weight gain. To maintain muscle and bone mass, try weight-bearing exercises such as push-ups, sit-ups, or lifting weights. To prevent weight gain, try aerobic exercise to increase your heart rate. Examples of aerobic exercise include fast walking, jogging, cycling, and swimming. Consult your doctor before beginning any exercise program. For more information, see the topic Fitness.
- Avoid possible falls by removing loose rugs and other hazards from your home. Falling may lead to broken bones and other injuries.
- Pay close attention to all wounds. Too much cortisol slows wound healing. Clean all wounds immediately with antibacterial soap and use antibiotic ointment and dressings to prevent infection.
- Seek counseling if you need help dealing with changes in your body image.
- Get regular eye exams to check for glaucoma and cataracts.
- See your doctor regularly to help diagnose and treat diabetes, high blood pressure, and other potential complications.
If you do not have Cushing's syndrome but are taking corticosteroid medicines, talk to your doctor about whether you are at risk for developing the syndrome. Your doctor may reduce your dosage, treat your condition with a different medicine, or prescribe a shorter-acting corticosteroid medicine.
Other Places To Get Help
|Cushing's Support and Research Foundation, Inc.|
|65 East India Row|
|Boston, MA 02110|
The Cushing's Support and Research Foundation offers consumer pamphlets and other information. The organization also publishes a newsletter.
|National Adrenal Disease Foundation|
|505 Northern Boulevard|
|Great Neck, NY 11021|
The National Adrenal Diseases Foundation is a consumer-based organization providing information and support for people with adrenal-related diseases.
|Pituitary Network Association (PNA)|
|P.O. Box 1958|
|Thousand Oaks, CA 91358|
The Pituitary Network Association is a nonprofit organization that provides support for people who have pituitary tumors and disorders.
- Miller WL, Chrousos GP (2001). Cushing's syndrome section of The adrenal cortex. In P Felig, LA Frohman, eds., Endocrinology and Metabolism, 4th ed., pp. 476–511. New York: McGraw-Hill.
- Stewart PM (2008). Corticosteroid hormone action section of The adrenal cortex. In HM Kronenberg et al., eds., Williams Textbook of Endocrinology, 11th ed., pp. 453–477. Philadelphia: Saunders.
Other Works Consulted
- Dambro MR (2006). Cushing disease and syndrome. In Griffith's 5-Minute Clinical Consult 2006. Philadelphia: Lippincott Williams and Wilkins.
- Aron DC, et al. (2007). Cushing's syndrome. In DG Gardner et al., eds., Greenspan's Basic and Clinical Endocrinology. 8th ed., pp. 378–389. New York: McGraw-Hill.
|Author||Caroline Rea, RN, BS, MS|
|Editor||Susan Van Houten, RN, BSN, MBA|
|Associate Editor||Pat Truman, MATC|
|Primary Medical Reviewer||Caroline S. Rhoads, MD - Internal Medicine|
|Specialist Medical Reviewer||David C.W. Lau - Endocrinology|
|Last Updated||April 29, 2008|
Last Updated: April 29, 2008