Cushing's Syndrome
Definition
Cushing's Syndrome is a rare disorder that develops when the body is exposed to too much of the hormone cortisol. Cushing's Syndrome is also known as hypercortisolism.
Normally, cortisol levels increase through a chain reaction of hormones. The brain's hypothalamus produces corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to make adrenocorticotropic hormone (ACTH). Then, ACTH stimulates the adrenal glands to produce cortisol.
Cortisol affects almost every area of the body and is particularly 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 develop one or more symptoms. Cushing's Syndrome may cause weight gain, skin changes, and fatigue and lead to such serious conditions as diabetes, high blood pressure, depression, and osteoporosis. If untreated, Cushing's Syndrome can cause death.
Causes
Cushing's Syndrome may be caused by:
- Taking corticosteroid medicine after an organ transplant or for long-term (chronic) conditions such as lupus, asthma, rheumatoid arthritis, or other diseases that cause inflammation. This is the most common cause of Cushing's Syndrome.
- Small, noncancerous (benign) tumors on the pituitary gland. This is called Cushing's Disease and is the second most common cause of Cushing's Syndrome.
- Benign and cancerous tumors on the adrenal glands that make cortisol.
- Benign and cancerous tumors on the lung and less often the pancreas that make ACTH. These organs normally do not make ACTH.
Symptoms
Weight gain and obesity—especially around the waist—are the most common symptoms. Because cortisol affects almost all body systems, many symptoms may develop. They include:
- Muscle weakness.
- Changes in the skin, such as bruising, acne, and dark purple-red stretch marks on the abdomen called striae.
- Changes in mood, such as irritability, anxiety, and depression.
- Extra fat on the back of the neck and upper back.
- Backaches.
- Loss of muscle tone.
- Menstrual irregularity.
- Abnormal hair growth (such as facial hair in women).
The signs and symptoms of Cushing's Syndrome generally develop gradually.
Sometimes alcoholism, depression, panic attacks, obesity, or other conditions can cause symptoms similar to Cushing's Syndrome. This is known as pseudo-Cushing's Syndrome. Symptoms usually stop when these conditions are treated. Antiviral therapies used in the treatment of HIV also may cause pseudo-Cushing's Syndrome.
Diagnosis
Your doctor will use your medical history, a physical examination, and laboratory tests to diagnose Cushing's Syndrome. During the physical examination, he or she will look for signs of the condition. The medical history includes questions about any symptoms you have, what medicines you are taking, and, if you are a woman, whether your menstrual periods are regular.
If your doctor thinks you may have Cushing's Syndrome, you will have laboratory tests to check the level of cortisol in your blood and urine. Further testing may be needed to find the cause of high cortisol levels.
Treatment
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:
- About 85% of the time if the tumor is less than 1 cm (0.4 in.) in diameter.
- About 25% of the time if the tumor is 1 cm (0.4 in.) in diameter or larger.
Cushing's disease returns in about 2% of adults and up to 40% of children who have the operation. 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.
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
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.
This infomation was taken from the University of Michigan Health System's Health Library.
