Cushing's Syndrome

Cushing's syndrome is a rare hormonal disorder that occurs when the body produces excessive levels of cortisol for an extended period. The use of glucocorticoid hormones to treat other medical conditions (such as asthma) or tumors in the pituitary or adrenal glands are possible causes of Cushing's syndrome. Symptoms of Cushing's syndrome vary, but can include extreme weight gain, excess hair growth, and high blood pressure. Treatment for Cushing's syndrome may involve surgery, radiation therapy, chemotherapy, cortisol-inhibiting drugs, or a combination of treatments.

 

What Is Cushing's Syndrome?

Cushing's syndrome is a hormonal disorder that occurs when a person's tissues are exposed to an excess of the hormone cortisol. Cushing's syndrome is sometimes called "hypercortisolism."
 

How Common Is Cushing's Syndrome?

Cushing's syndrome is fairly rare. For every 1 million people, two to five new cases are diagnosed each year, with about 10 percent of these being children and teenagers.
 
Cushing's syndrome commonly affects adults between the ages of 20 and 50.
 

Understanding Cortisol

Normally, the production of cortisol follows a precise chain of events. First, the hypothalamus, a part of the brain that is about the size of a small sugar cube, sends corticotropin-releasing hormone (CRH) to the pituitary gland. CRH causes the pituitary to secrete ACTH (adrenocorticotropin), a hormone that stimulates the adrenal glands. When the adrenals, which are located just above the kidneys, receive the ACTH, they respond by releasing cortisol into the bloodstream.
 
Cortisol performs vital tasks in the body. Cortisol helps:
 
  • Maintain blood pressure and cardiovascular function
  • Reduce the immune system's inflammatory response
  • Balance the effects of insulin in breaking down sugar for energy
  • Regulate the metabolism of proteins, carbohydrates, and fats
  • Assist the body as it responds to stress.
     
When the amount of cortisol in the blood is adequate, the hypothalamus and pituitary release less CRH and ACTH. This ensures that the amount of cortisol released by the adrenal glands is precisely balanced to meet the body's daily needs. However, if something goes wrong with the adrenals or with their regulating switches in the pituitary gland or the hypothalamus, cortisol production can be affected, resulting in the symptoms of Cushing's syndrome.
 

Causes of Cushing's Syndrome

Cushing's syndrome can be caused by taking glucocorticoid hormones, such as prednisone, for:
 
Other people may develop Cushing's syndrome as a result of an overproduction of cortisol by the body. Some of the common causes of Cushing's syndrome in which the body produces too much cortisol include:
 
(Click Cushing's Syndrome Causes for more information.)
 

Symptoms of Cushing's Syndrome

Too much cortisol in the body for long periods of time is responsible for the classic Cushing's syndrome symptoms. Symptoms of Cushing's syndrome may vary based on the person's age.
 
Common symptoms of Cushing's syndrome can include:
 
  • Extreme weight gain, especially around the midsection and upper back
  • Excess hair growth
  • Purplish-pink stretch marks on the abdomen, thighs, buttocks, arms, and breasts
  • Acne
  • High blood pressure
  • Skin problems
  • Growth retardation
  • Either very early or very late puberty
  • Sleep disturbances
  • Muscle weakness
  • Menstrual disorders in women
  • Osteoporosis
  • Moodiness, irritability, or depression
  • Diabetes
  • Decreased fertility in men
  • Diminished or absent desire for sex.
     

Diagnosing Cushing's Syndrome

In order to make a Cushing's syndrome diagnosis, the doctor will ask a number of questions concerning subjects such as:
 
  • The patient's medical history
  • His or her current symptoms
  • Whether there is a family history of any medical problems
  • What medicines the patient is taking.
 
The doctor will also perform a physical exam, looking for any signs of Cushing's syndrome. If these suggest Cushing's syndrome, more tests are done.
 
Testing for Cushing's syndrome typically involves a two-step process. First, doctors order a test to see if there is too much cortisol in the body. This test is called a 24-hour urinary free cortisol level, and it measures how much cortisol is being produced.
 
If Cushing's syndrome is present based on the urine test, then doctors order further tests to determine the Cushing's syndrome cause.
 
These Cushing's syndrome tests may include:
 
  • Dexamethasone suppression test
  • CRH stimulation test
  • Dexamethasone-CRH test
  • Petrosal sinus sampling
  • Imaging tests.
 
(Click Cushing's Syndrome Testing for more information.)
 

Treating Cushing's Syndrome

Cushing's syndrome treatment depends on the specific reason for excess cortisol. Some options for Cushing's syndrome treatment include:
 
  • Surgery
  • Radiation
  • Chemotherapy
  • Cortisol-inhibiting medicines
  • A combination of these treatments.
     
(Click Cushing's Syndrome Treatment for more information on treatment for specific causes of Cushing's syndrome.)
 

Prognosis for Cushing's Syndrome

The prognosis for Cushing's syndrome varies depending on the cause of the disease. Most cases of Cushing's syndrome can be cured. Many individuals with Cushing's syndrome show significant improvement with Cushing's syndrome treatment, although some may find recovery complicated by various aspects of the causative illness. Also, some types of tumors may return.
 
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Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD