Cushing's Syndrome

What  is Cushing's syndrome?

Cushing's syndrome occurs when your body  is exposed  to high levels of the hormone cortisol for a long period of time. Cortisol is also sometimes  called a "stress hormone" and  is a natural steroid hormone that's like  the "cortisone" in some medicines. Cushing's syndrome can  be caused by  the body making too much cortisol  or it can be caused by taking too much corticosteroid medicines (which contain cortisol). 

What causes Cushing's syndrome?

The most common cause of  Cushing's syndrome is taking corticosteroids orally (by mouth) every day for weeks to months. These medicines  are usually prescribed  to treat inflammatory disease,  such as lupus and rheumatoid arthritis. Prednisone is the most common corticosteroid medicine that's taken this way. Other medicines include dexamethasone and methylprednisone. 

Inhaled steroid medicines for asthma and steroid skin creams for eczema and  other skin conditions don't usually cause Cushing's syndrome. Even oral medicines taken every day for short periods of time  or every other day  for longer periods don't often cause Cushing's syndrome. 

The next most common cause of  Cushing's syndrome is when  the body makes too much cortisol. A tumor in  the pituitary gland can be one cause  of Cushing's syndrome. The pituitary gland is located at the bottom  of the brain and controls  the body's production  of cortisol. These  small tumors can cause  the adrenal glands,  which are near  the kidneys, to make too much cortisol. 

The tumors on  the pituitary gland  in Cushing's syndrome aren't usually malignant (cancercous).  However, if these tumors get too big, they can cause problems  with your eyesight. 

What  are the symptoms  of Cushing's syndrome? 

The following  are some  of the symptoms  of Cushing's syndrome: 

• Fat deposits that form around  the abdomen and upper back (a hump  often forms between  the shoulders)
• Thinner skin that is easily bruised 
• Cuts, scratches and insect bites that take a long time to heal 
• Pink  or purple stretch marks on your skin (especially  the arms, breasts, adbomen  and thighs) 
• Round  and puffy face 
• Muscle weakness 
• Depression
• Acne 
• Irritability
• Irregular menstrual periods in women 
• Thicker  or more visible hair on  the face  and body (usually more noticeable in women) 
• Erectile dysfunction in men 
• High blood pressure 
• Osteoporosis (weak and brittle bones) 
• High blood sugar levels 

How is Cushing's syndrome diagnosed?

Your doctor may start by asking you questions about your  medical history and doing a  physical exam. If  the cause is a medicine you  are taking, no  tests are usually needed. If your doctor thinks that you have  Cushing's syndrome but you  are not taking medicines that can cause it, you may need  to have some blood and urine tests. These tests measure  the amount  of cortisol in your body. 

You may be asked  to collect your urine for 24 hours. You may also be  given a medicine called  dexamethasone before your  blood or urine is collected. This tests your body's  response to steroids. 

At some point, you may need a computerized tomography (CT) scan  or a magnetic  resonance imaging (MRI) scan.  These tests take  a picture of your insides. Looking at these pictures, your doctor will be able to tell whether there  are tumors on  the pituitary gland or  in other parts  of your body  that may be causing  Cushing's syndrome.

How are Cushing's disease and  syndrome treated?

If a coritcosteroid medicine  is causing Cushing's syndrome, your  doctor will gradually lower your  dose over time. Abruptly stopping  a corticosteroid  can cause  a dangerous  drop in your  cortisol levels, so you should never  stop taking these medicines without your doctor's approval. Your doctor may also prescribe  a noncorticosteroid medicine  to replace the corticosteroid  that was causing Cushing's syndrome. 

If a pituitary gland tumor is causing Cushing's  syndrome, your doctor will surgically remove  it from your pituitary gland. This  type of surgery is usually successful. Radiation treatments  are sometimes  used after surgery  to lower the risk  that the tumor will come back. You'll need  to take  a cortisol replacement medicine after  the tumor  is removed because it will take your body  some time before it starts producing normal amounts of cortisol. Most people only need  to take  the cortisol replacement medicine for a few months, but it could take up  to year.  In rare cases, people who  have had surgery  to remove a  tumor that was causing  Cushing's syndrome never regain normal cortisol levels and must therefore continue  to take  the cortisol replacement medicine.