What is Cushing's syndrome?
Cushing's syndrome is a rare problem that happens when you have too much of the hormone cortisol in your body. Cortisol is especially important in controlling blood pressure and metabolism. But it affects almost every area of your body.
Normally, your body keeps the level of cortisol in balance through a complex system that involves three glands.
- When your cortisol level gets low, a part of the brain called the hypothalamus releases a hormone called CRH.
- CRH tells the pituitary gland, located beneath the brain, to make a hormone called ACTH.
- ACTH triggers the adrenal glands, which sit above the kidneys, to release cortisol.
If something upsets this system, your cortisol level can get too high. If it's high for too long, it can cause symptoms and can lead to serious problems, such as diabetes, high blood pressure, depression, and osteoporosis.
Another name for Cushing's syndrome is hypercortisolism.
What causes Cushing's syndrome?
The most common cause is taking steroid medicines, such as prednisone, for a long time. These medicines act like cortisol in your body. They are used to treat many diseases, including lupus, asthma, and rheumatoid arthritis. They are also used after an organ transplant.
You can also get Cushing's syndrome because your body makes too much cortisol. This can happen if you have:
- A tumor in your pituitary gland that makes extra ACTH, and that causes the adrenal glands to make more cortisol. This is called Cushing's disease. These tumors usually aren't cancer.
- A tumor in your lung or pancreas that makes ACTH, and that causes the adrenal glands to make more cortisol. Sometimes these tumors are cancer.
- A tumor in your adrenal glands that makes extra cortisol. Some of these tumors are cancer.
What are the symptoms?
The symptoms vary and often appear slowly over time. You may have:
- Weight gain, especially around the waist. This is the most common symptom. You might also have a round face or extra fat around the neck and upper part of the back (buffalo hump).
- Skin changes, such as bruising, acne, or dark purple-red stretch marks on your belly.
- Mood changes, such as feeling irritable, anxious, or depressed.
- Muscle and bone weakness. This may cause backaches, broken bones (especially the ribs and spine), or loss of muscle tone and strength.
- Changes in sex hormone levels. In women, this may cause irregular periods and growth of facial hair. In men, it may cause erection problems or changes in sex drive.
How is Cushing's syndrome diagnosed?
Cushing's syndrome can be hard to diagnose because many things can make your cortisol level higher than normal. You may need to see a doctor who specializes in hormone disorders (endocrinologist) to diagnose or treat Cushing's syndrome.
To find out if you have Cushing's syndrome, a doctor will:
- Ask questions about the medicines you take, your symptoms, and, if you are a woman, your periods.
- Take your blood pressure, look for skin changes, and check for changes in your weight and for any signs of cancer.
A doctor can usually find out from these exams if steroid medicine is causing the problem.
If you don't take steroid medicine or your doctor thinks something other than medicine is causing your symptoms, you may have tests, such as:
- Tests to check the level of cortisol and other hormones in your blood and urine.
- A test to measure cortisol in your saliva in the late evening, when the level normally drops.
- A CT scan or MRI to look for a tumor on your adrenal glands, pituitary gland, or another organ.
How is it treated?
If long-term use of steroid medicine is the cause:
- Your doctor will help you lower your dose or gradually stop taking it. It may take a while for the symptoms to go away.
- Do not stop taking steroid medicine on your own. That can be very dangerous. Your doctor will help you change your medicine or lower the dose slowly.
If a pituitary tumor is the cause:
- Surgery to remove the tumor offers the best chance for recovery. This surgery requires great skill and should be done at a major medical center where doctors specialize in pituitary surgery.
- If surgery to remove the tumor isn't possible or hasn't worked, you may have other options to consider such as medicine, radiation, or surgery to remove the adrenal glands. You and your doctor can talk about the pros and cons of each option.
If an adrenal tumor is the cause:
- Surgery to remove the tumor is usually done if the tumor is not cancer (benign). If the tumor is cancer, the whole gland is removed.
- Medicine may be tried if surgery isn't an option.
If a tumor of the lungs or another organ is the cause, the tumor will be removed or treated with radiation or medicines.
What changes can you make to help with Cushing's syndrome?
There are many things you can do to prevent weight gain, strengthen your muscles and bones, and avoid health problems from Cushing's syndrome.
Eat a healthy diet
- Choose a variety of low-calorie foods that are high in protein and calcium. This can help prevent muscle and bone loss caused by high cortisol levels.
- Take calcium and vitamin D supplements to decrease bone loss. Ask your doctor whether you need medicine to help slow bone loss.
- Limit salt (sodium) in your diet. This is especially important if you have high blood pressure.
Take good care of yourself
- Get regular exercise. Weight-bearing exercise can help keep your bones and muscles strong. Aerobic exercise can help prevent weight gain. Talk to your doctor before you start any exercise program.
- Avoid falls, which can lead to broken bones and other injuries. Remove loose rugs and other tripping hazards from your home.
- Get regular eye exams to check for glaucoma and cataracts.
- See your doctor regularly to watch for other problems such as diabetes, high blood pressure, and osteoporosis.
Other Works Consulted
- Almeida MQ, Stratakis CA (2011). Cushing's syndrome. In ET Bope et al., eds., Conn's Current Therapy 2011, pp. 653–659. Philadelphia: Saunders.
- Carroll TB, et al. (2011). Glucocorticoids and adrenal androgens. In DG Gardner, D Shoback, eds., Greenspan's Basic and Clinical Endocrinology, 9th ed., pp. 285–327. New York: McGraw-Hill.
- Nieman L, et al. (2008). The diagnosis of Cushing's syndrome: An Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology and Metabolism, 93(5): 1526–1540.
- Nieman LK, et al. (2015). Treatment of Cushing's syndrome: An Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology and Metabolism, 100(8): 2807–2831. DOI: 10.1210/jc.2015-1818. Accessed February 23, 2016.
- Stewart PM, Krone NP (2011). The adrenal cortex. In S Melmed et al., eds., Williams Textbook of Endocrinology, 12th ed., pp. 479–544. Philadelphia: Saunders.
Current as of: November 6, 2018
Author: Healthwise Staff
Medical Review: E. Gregory Thompson, MD - Internal Medicine
Kathleen Romito, MD - Family Medicine
David C. W. Lau, MD, PhD, FRCPC - Endocrinology
Matthew I. Kim, MD - Endocrinology, Diabetes and Metabolism