Cushing's syndrome

Cushing’s syndrome is a collection of hormonal disorders characterised by high levels of the hormone cortisol. Another name for Cushing’s syndrome is hypercortisolism. Some people have Cushing’s syndrome symptoms when they take glucocorticoid hormones to treat inflammatory conditions such as asthma, lupus or rheumatoid arthritis. Other causes include tumours of the pituitary and adrenal glands, and tumours in other areas of the body. Around one in 50,000 people are affected by Cushing’s syndrome, with females more susceptible to some forms than males. Without treatment, the disorder can be fatal.

Symptoms

Some of the symptoms include:

• Weight gain around the abdomen, and obesity
• Wasting of the limbs
• A ‘buffalo’ hump of fat high on the back
• Round, red and puffy-looking face (‘moon face’)
• Thin skin, easily bruised, slow healing and ulcers
• Muscular weakness
• Thirst
• Frequent urination
• Headaches
• High blood pressure
• High white blood cell count, low serum potassium
• High blood sugar (in 80 per cent of patients)
• Mood swings, irritability, anxiety, depression
• Impotence
• Irregular menstrual periods or no menstrual periods
• Increased facial hair in women
• Weakened bones, susceptibility to bone fractures (especially in ribs and spine), osteoporosis and backache
• Susceptibility to pneumonia and TB.

The hormone cortisol

Cortisol is made by the adrenal glands. When cortisol levels are too low, the pituitary secretes the stimulating hormone adrenocorticotropin (ACTH). High levels of cortisol prompt the pituitary to decrease ACTH, which slows cortisol production. Cortisol is essential to life. Its functions include:

• Helping the body manage stress
• Helping to maintain constant blood sugar levels
• Inhibiting inflammation
• Contributing to the maintenance of constant blood pressure
• Contributing to the workings of the immune system.

A range of causes

The symptoms of Cushing’s syndrome are caused by damage to body tissues due to high levels of the hormone cortisol in the blood over a long time. The disorders that trigger high cortisol levels include:

• Tumour of the pituitary gland
• Tumour of the adrenal gland
• ACTH-producing tumours (ectopic) elsewhere in the body
• Multiple endocrine neoplasia 1 (MEN1)
• Glucocorticoid hormone therapy.

Tumour of the pituitary gland

This form is known as Cushing’s disease and accounts for about seven in 10 cases of Cushing’s syndrome. One type of pituitary gland tumour secretes additional ACTH, which forces the adrenal glands to make too much cortisol. The tumours are usually benign non-cancerous adenomas and they occur more often in women than men (3:1). Complications include diabetes, kidney stones and mental disturbances, such as psychosis.

Tumour of the adrenal gland

This form of Cushing’s syndrome is also known as Cushing’s disease. A tumour on one of the adrenal glands triggers the production of high cortisol levels. The tumours are usually non-cancerous. The pituitary responds by dropping its level of ACTH hormone, which causes the healthy adrenal gland to shrink. Onset of symptoms can be quite rapid, and tends to occur at around 40 years of age.

ACTH-producing tumours

In rare cases, other malignant tumours in the body can produce ACTH. Approximately 17 per cent of Cushing’s disease develops this way. Fifty per cent of cases result from lung tumours. Other causes come from tumours in the thymus, pancreas and thyroid gland. This type of Cushing’s syndrome is sometimes referred to as ‘ectopic’.

Multiple endocrine neoplasia 1 (MEN1)

The pituitary, pancreas, adrenals, thyroid and parathyroid glands belong to the endocrine system. MEN1 is an inherited condition characterised by tumours on at least two of these glands. If the pituitary or adrenals are affected, Cushing’s syndrome can result.

Primary Pigmented Micronodular Adrenal Disease occurs in children and young adults, where there is an increase in the number of cortisol-producing adrenal tumours.

Glucocorticoid hormone therapy

Glucocorticoid drugs are commonly used to ease the symptoms of inflammatory conditions such as asthma, rheumatoid arthritis and lupus erythematosus. These drugs can trigger symptoms of Cushing’s syndrome. However, the effects should reverse once the drug therapy is stopped.

Diagnosis methods

Diagnosis for Cushing’s syndrome involves discovering the high cortisol levels and uncovering the cause. Diagnosis methods may include:

• Physical and visual examination, with full family medical history.
• Blood tests to check if Cushing’s is of pituitary or ectopic origin and to compare ACTH levels elsewhere in the body. A combination of these two tests gives great accuracy for diagnosis.
• Urine tests.
• Dexamethasone suppression test using steroids to check the body’s reaction to glucocorticoid drugs.
• Magnetic resonance imaging (MRI) scans and computed tomography (CT) scans to check for gland size and evidence of tumours.

Treatment options

Treatment depends on the cause and may include:

• Tumour of the pituitary gland - the tumour is surgically removed. Other options include radiation therapy and drug therapy to shrink the tumour and stop it from producing hormones. Hormone therapy for up to two years after surgery may also be required.
• Tumour of the adrenal gland - the tumour is surgically removed. Replacement hormone therapy may be necessary in the short term.
• ACTH-producing tumours - treatment includes surgery to remove the tumour, followed possibly by chemotherapy, immunotherapy and radiation therapy. Medications can be taken to hamper the ability of the adrenal glands to make cortisol.
• MEN 1 - radiation therapy and surgery are used to remove the tumours and associated glands. Ongoing hormone replacement therapy is needed after surgery.
• Glucocorticoid hormone therapy - induced Iatrogenic Cushing’s Syndrome - symptoms disappear and the effects reverse once the drugs are stopped. Occasionally a person may need glucocorticoid hormones to successfully manage their inflammatory disorder.

Where to get help

• Your doctor
• Endocrinologist
• The Australian Addison's Disease Association Inc. Tel. (02) 6652 4761; (02) 6657 2571.

• Australian Pituitary Foundation Tel. 1300 331 807 email: support@pituitary.asn.au
• The Western Australian Cushing's Disease Association Tel. (08) 9402 4394; (08) 9390 2132.

Things to remember

• Cushing’s syndrome is a collection of hormonal disorders resulting from high levels of the hormone cortisol.
• Causes include certain tumours and glucocorticoid drug therapy for inflammatory disorders.
• Without treatment, Cushing’s syndrome can be fatal.

You might also be interested in:

• Addison's disease.
  
• Congenital adrenal hyperplasia.
  
• Hormonal (endocrine) system.
  
• Hormones - cortisol.
  
• Hyperglycaemia.
  
• McCune-Albright syndrome.
  
• Pituitary tumour.
  

Want to know more?

Go to More information for support groups, related links and references.

This page has been produced in consultation with and approved by:

(Logo links to further information)

Australian Addisons Disease Association

Fact sheet currently being reviewed.
Last reviewed: August 2010

Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.

If you would like to link to this fact sheet on your website, simply copy the code below and add it to your page:

<a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Cushing's_syndrome?open">Cushing's syndrome - Better Health Channel</a><br/>
Cushing's syndrome, or hypercortisolism, is a collection of hormonal disorders characterised by high levels of the hormone cortisol. Causes include tumours of the pituitary and adrenal glands, certain tumours in other areas of the body, and sometimes glucocorticoid therapy for inflammatory disorders.

Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your qualified health professional. Content has been prepared for Victorian residence and wider Australian audiences, and was accurate at the time of publication. Readers should note that over time currency and completeness of the information may change. All users are urged to always seek advice from a qualified health care professional for diagnosis and answers to their medical questions.

For the latest updates and more information, visit www.betterhealth.vic.gov.au

Copyight © 1999/2012  State of Victoria. Reproduced from the Better Health Channel (www.betterhealth.vic.gov.au) at no cost with permission of the Victorian Minister for Health. Unauthorised reproduction and other uses comprised in the copyright are prohibited without permission.