What is Cushing's

What is Cushing’s?

This syndrome develops if your body makes too much cortisol hormone.

Symptoms usually develop gradually and so the diagnosis may not be clear for some time.

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Cortisol is a hormone made by the adrenal glands (two small glands which lie just above

each kidney) and it is vital for life. It has several functions including:

• Helps to regulate blood pressure

• Helps to regulate the immune system

• Helps to balance the effect of insulin to keep blood sugar normal

• Helps the body to respond to stress

The most common reason for Cushing's overall is glucocorticoid treatment - for example taking a steroid such as prednisolone for asthma, arthritis or colitis.

The quoted incidence of Cushing’s is 1 in 200,000 but it is now being found more frequently when it is specifically investigated. The difficulty is that the symptoms of Cushing’s can be very wide ranging and thus the diagnosis may not necessarily be considered

Cushing's is rare and is more often found in women than in men. It can affect all age groups, but the peak incidence is in middle age.

Typical symptoms of Cushing's disease

  • behaviourial changes, depression and mood swings, occasionally psychological problems can be severe
  • face tends to be rounder (moon face) and redder
  • weight gain around the trunk (central obesity)
  • muscle wasting and proximal myopathy (patients have difficulty standing from a seated position without use of arms)
  • tendency to bruise easily
  • appearance of red 'stretch marks' on the abdomen, similar to those which occur during pregnancy
  • irregular periods (Oligomenorrhoea) or loss of normal menstrual function (Amenorrhoea) - females
  • impotence - males
  • reduced fertility
  • decrease in sex drive
  • increase in hair growth on the face and body (hirsutism)
  • increase in blood pressure
  • development of mild diabetes mellitus

How is Cushing's diagnosed?

The tests used to diagnose Cushing’s are complicated and may take some time; they may also need to be repeated on several occasions. You may have them as an inpatient or an outpatient.

The first tests are to establish that Cushing’s is present. If Cushing’s is likely then further tests establish the location.

This is because most people who gain weight and who have high blood pressure or diabetes or problems with excess hair do not actually have Cushing’s. To see if you have Cushing’s you will probably be given a tablet called dexamethasone.

In people who do not have Cushing's, taking this tablet will completely suppress the production of the hormone cortisol. You may also have a series of blood tests and urine tests and even saliva tests.

The urine test involves collecting all the urine you pass during 24 hours (for example, between nine o'clock one morning and nine o'clock the next morning). The hospital will provide a special container for this and you will be told how to take accurate and clean samples.

If these initial tests indicate that Cushing's is likely, you will then need further tests to find its location.

You may be admitted to hospital for these, and it is likely that you may be referred to a hospital where they are very familiar with Cushing’s. Tests include blood samples taken throughout the day; a higher dose of dexamethasone; an injection of corticotrophin releasing hormone (CRH) which stimulates the pituitary; and lastly measuring the blood coming from the pituitary gland.

Your doctor may decide to treat you in the meantime with drugs, such as metyrapone or ketoconazole, to reduce the amount of cortisol produced by your adrenal glands. If so, you may have to spend two or three days in hospital to assess your response to the tablets or attend regularly as an outpatient.

You will also have your pituitary and/ or adrenal glands scanned, using a type of magnetic scan called an MRI scan, or by a form of X-Ray called a CT scan. You may be given an injection during the scan to improve the results. A minority of patients are allergic to this injection; so do tell the specialist if you have asthma or any allergies. The scan does not hurt.

How Cushing’s is treated?

If your Cushing's is caused by a pituitary tumour (Cushing's disease), you will usually need an operation. It is carried out under a general anaesthetic and involves making a small cut - either in front of the upper teeth behind the upper lip or inside the nose. This is called transsphenoidal surgery.

By going behind the nose in this way, the surgeon can see your pituitary gland without having to operate on the main part of your head.

Please see our booklet on Surgery & Radiotherapy.

Most people are up and about and eating normally the following day and are back at home within a few days. Recovery times can vary. Depending on your particular job and circumstances, you should plan to be away from work for four to six weeks, maybe longer.

After surgery

Many patients will be completely cured – their cortisol levels are no longer high - after pituitary surgery but your doctor may prefer to be cautious and call this “remission” until some years have passed. However, if the treatment of your pituitary gland is not fully effective, then there are other solutions.

You may need to have both adrenal glands removed. This is called an adrenalectomy.

With modern ‘keyhole’ techniques, recovery from the operation is quick and inpatients stay only a few days. After an adrenalectomy you will need hydrocortisone tablets and an additional salt-retaining hormone tablet (called fludrocortisone)