What is Cushing’s and why do we get it?
Cushing’s 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.
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
Spontaneous Cushing’s, originating from within the body is rare, but occurs when the adrenal glands are making too much of a hormone called cortisol (the body’s natural glucocorticoid steroid hormone). This may happen for one of several reasons so you will have tests to find out which reason applies to you. The difficulty is that the symptoms of Cushing’s can be very wide ranging; it can be difficult to establish, at the earlier stages and this can cause a delay in diagnosis.
The commonest cause of spontaneous Cushing’s (around 70%) is a small benign tumour (growth) of the pituitary gland. This produces the hormone called ACTH, (adrenocorticotrophic hormone), that goes through the blood stream to the adrenal glands and causes them to release too much cortisol..
Alternatively, there could be a small growth in another part of your body which is having the same effect (this is called ectopic ACTH). If so, removing this growth will usually solve the problem. Strictly speaking, if the source of the problem is the pituitary gland, then the correct name is Cushing’s Disease Sometimes, the amount of cortisol causing the condition can vary greatly. This is called ‘Cyclical Cushing’s’ with symptoms varying.
What are the symptoms of Cushing’s?
- Symptoms of having Cushing’s are very varied, and usually several are present; these can include:
- Excessive and sudden (or at times more gradual) onset of weight gain around your trunk (your arms and legs may remain unchanged and can become quite thin compared to your body)
- Weak muscles, especially in your legs
- Your face tends to be rounder and redder than normal (a classic symptom of Cushing’s known as ‘moon face’) and you may have developed acne
- Your bones may have become weaker due to steroid-induced osteoporosis (thinning and brittleness of bones) – increased risk of fracture.
- High blood pressure (hypertension) – developed diabetes mellitus (‘sugar diabetes’) and excess thirst
- A tendency to bruise easily and have deep red/purple stretch marks (striae) appearing on the abdomen,
Irregular periods or stop having them altogether
- Excessive hair growth on parts of the body and usually the face in women
- Men can experience decreased fertility and both men and women can feel a reduction, or absence of sex drive (libido)
- You may be feeling generally unwell, and more susceptible to infections
- Mood swings – more irritable, feeling depressed or anxious. In some cases, psychological problems can be severe, even being diagnosed as a nervous breakdown
- In children it may show itself by growth stopping and weight increasing
Cushing’s affects many parts of the body, both mentally and physically, and affects different people in different ways.
Because Cushing’s progresses slowly and gradually, in most cases, it can go unrecognised for quite some time, sometimes resulting in depression.
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.
The first tests are to establish that Cushing’s is present. You will probably be given a tablet called dexamethasone.. 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 .
You will then need further tests to confirm Cushing’s and you may be admitted to hospital for these. 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.
You will also have your pituitary and/ or adrenal glands scanned, using 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.
How is Cushing’s 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.
Following surgery, you may also notice peeling of the skin as the cortisol levels fall (this is a good sign).
After successful surgery you may feel worse for several weeks and occasionally months before you begin to feel better. Eventually, however, your strength and mood will improve over time and the other symptoms will gradually diminish. This usually takes several months, but be patient – it will happen. You may have to take replacement cortisol (which is called ‘hydrocortisone’ when it is in tablet form) or another steroid tablet such as prednisolone, for some time after your operation to compensate for a temporary reduction in your body’s ACTH production. This occurs because the normal control mechanisms are ‘switched off’ after being exposed to too much cortisol for so long. Hydrocortisone is taken in the form of tablets, usually two or three times a day.