Cushing's Syndrome

What is Cushing's syndrome?

Cushing's syndrome is a hormone problem. It happens when your body is suffering the effects of too much cortisol. It can result when:

Your body is making too much cortisol.
You are taking too much steroid medicine (the more common cause).

Cortisol is a hormone made by the body. It has many important functions. One of the most important is maintaining the body during physical stress, for example, keeping the blood pressure normal in spite of blood loss from an accident. The body makes extra cortisol during the stress of emotional problems such as depression as well as during physical illness and surgery. Cortisol is also very important in the body's metabolism and use of the nutrients you get from the food you eat every day.

Cushing's syndrome is also sometimes called hypercortisolism.

How does it occur?

Cortisol is made in the adrenal glands, two small glands that sit on top of each kidney. The amount of cortisol the body makes is controlled by the brain and the pituitary gland. When the body is making too much cortisol, it usually is because of a tumor in one of your glands. The tumors may be benign (noncancerous) or malignant (cancerous). Common tumors are:

pituitary adenoma, which is a benign growth in the pituitary gland
adrenal tumors, which are usually benign growths in the adrenal gland.

Occasionally other tumors, both benign and malignant, can cause your body to make too much cortisol. These tumors are often in the lung, but they can be in glands as well, such as the thyroid or pancreas.

Most Cushing's syndrome, however, is caused by taking cortisol as medicine. A common example of one of these medicines is prednisone. As a group, the medicines are called corticosteroids, glucocorticoids, or steroids.

Because cortisol has so many functions in the body, it can be very helpful for many medical problems. Cortisol is a natural anti-inflammatory, so it is used to stop or reduce the effects of diseases where inflammation is the main problem, such as asthma, rheumatoid arthritis, and lupus. In some cases the cortisol is taken on a regular basis and in others it is taken only at times when the disease is active or causing symptoms (flares).

Cortisol is also used to help stop the rejection of transplanted organs. Cortisol may need to be taken for the rest of your life, if you have had a kidney or other type of transplant.

In these situations you and your healthcare provider have to weigh the side effects of the medicine against the benefits of the treatment.

What are the symptoms?

The most common symptoms of hypercortisolism are:

round face (often called moon face)
increased fat in the trunk area, that is, the abdomen and the upper back (called buffalo hump)
easy bruising of the skin
stretch marks on the skin, especially the abdomen, breasts, and thighs
irritability
tiredness
increased facial and body hair in women and irregular or stopped menstrual periods
loss of interest in sex.

Because having too much cortisol can cause type 2 diabetes, you may also have the symptoms of diabetes, including increased thirst and urination, fatigue, and blurry vision.

If you had diabetes (type 1 or type 2) before you started having Cushing's syndrome, you may have trouble keeping good control of your blood sugar.

How is it diagnosed?

The diagnosis is often obvious from how you look. Your healthcare provider will take a careful history and examine you. During the exam your provider will look for signs of Cushing's syndrome: high blood pressure; thin, bruised skin; thinning arms and legs, and more fat in the upper body (trunk and abdomen).

If you have been taking steroid medicine, your provider will know the likely cause of your symptoms. The lab tests will be simpler and fewer than if the cause is not known. You will probably have blood tests to check your blood count, ability to clot your blood, mineral balance, blood sugar, and liver and kidney function.

If you have not been taking cortisol-type medicines, the following tests may be necessary:

skull X-ray, CT scan, or MRI
24-hour urine cortisol test
dexamethasone suppression test.

For the urine cortisol test, you collect your urine for 24 hours. The urine is then tested to see if you are making too much cortisol. For the dexamethasone test you are given different doses of dexamethasone to take by mouth for several days and you collect your urine as directed for testing in the lab. The test is done to see if your extra cortisol is from a pituitary tumor or a tumor in a different area.

How is it treated?

The treatment will depend on the cause of the extra cortisol. If the cause is steroid medicine you are taking, you and your healthcare provider will have to see if you can lower your dosage or try other medicines. In some cases your provider may have you try taking your steroid medicine every other day, which for many people causes fewer side effects.

If your body is making too much cortisol, then your treatment may involve surgery, chemotherapy, or radiation to treat a tumor.

How long will the effects last?

If the cause is steroid medicine, your symptoms will gradually lessen over several weeks to months as you decrease or stop your medicine. However, some or all of the symptoms are likely to return if you start taking the medicine again during a flare of your illness.

If you have a tumor making excess cortisol, your Cushing's syndrome symptoms will gradually decrease after the tumor is treated. You may need to be checked regularly after treatment to make sure the tumor does not come back.

How can I take care of myself?

Make sure you follow your healthcare provider's recommendations to prevent the complications caused by too much cortisol. You may need to check your blood pressure and your blood sugar regularly.

If you have become very weak or you may have lost some bone strength (osteoporosis), you may need physical therapy and an exercise prescription. This will help strengthen your muscles and bones.

What can I do to prevent Cushing's syndrome?

Doctors do not know how to prevent most of the tumors that cause Cushing's syndrome.

If you are taking steroid medicines for a medical problem, keep all of your follow-up appointments with your healthcare provider. Your provider will check for the signs of Cushing's syndrome and the problems it can cause. Researchers are looking for nonsteroid medicines that can treat inflammation and prevent transplant rejection. With time there may be medicines that can help your condition without the side effects of steroids.