Cushing Syndrome: Symptoms, Diagnosis And Treatment

You may known cortisol primarily as a stress hormone, but this natural steroid hormone actually plays a big role in the functioning of many body systems. Produced by the adrenal glands that sit on top of your kidneys, cortisol production is stimulated by another hormone called ACTH, which is produced by the pituitary gland.

In Cushing syndrome, sometimes called either hypercortisolism or Cushing's Syndrome, cortisol levels are elevated, setting off all the systems the hormone usually plays a role in. Cortisol increases blood glucose, stores fat and breaks down muscle protein.

What Causes Cushing Syndrome?

Cushing syndrome most commonly occurs as the result of an overdose or side effect of medications containing corticosteroids. Synthetic corticosteroids like Prednisone, dexamethasone and prednisolone mimic the action of cortisol. Corticosteroid drugs are commonly prescribed for a number of conditions, including asthma, inflammatory bowel disease, rheumatoid arthritis, lupus and many other autoimmune diseases.

There are other causes of Cushing syndrome in which body itself produces too much cortisol. This can be caused by a tumor of the adrenal glands or there may be a tumor of the pituitary gland producing excess ACTH, which in turn over-stimulates the adrenal glands — resulting in increased cortisol production. This condition is called Cushing “disease”

Cushing syndrome can also occur when a tumor outside of the pituitary gland produces ACTH. This is called Ectopic Cushing syndrome and is very rare.

Signs And Symptoms Of Cushing Syndrome

The symptoms of Cushing syndrome are brougt on by increased cortisol levels. Patients with Cushing syndrome usually present with:

• A red, rounded and full face caused by the deposition of fat (" full moon face").
• Central obesity, which means an overall weight gain with deposition of fat in the central part of the body (trunk), but a loss of fat from the limbs and buttocks.
• A hump between the shoulders due to collection of fat. It is called a “Buffalo hump”.
• Purple or pink stretch marks on the skin of abdomen, thigh or breasts called “striae”. Easy bruising of skin and skin infections are also seen. Slow healing of cuts and minor injuries.
• Osteoporosis, which means brittle bones. It is also associated with bone pains, especially backache. Weak bones — like the ribs and spine — are fractured easily.  
• Muscle weakness is a very common symptom. This occurs because cortisol increases the rate of muscle protein breakdown.
• Behavioral and psychological changes like anxiety, irritability and depression.
• Other symptoms include headache, fatigue, high blood pressure and increased urination.
• In women, Cushing syndrome is associated with menstrual irregularities and hirsutism which is excessive growth of hair on the face, chest, neck, thighs and abdomen.
• In men, it is associated with a decreased libido. Cushing syndrome may also cause impotence or erectile dysfunction.
• Children with Cushing syndrome are usually obese and have stunted growth

READ Most common uses of Corticosteroids

Please tell your doctor about any medications you are taking, and about all the symptoms you have and for how long  you've had them. The best way is to make a list of all the symptoms and medications. This will help the doctor in reaching a final diagnosis.

Diagnosis And Treatment Of Cushing Syndrome

Cushing syndrome may be difficult to diagnose because some other diseases present with similar symptoms. Therefore, history and physical examination only point towards Cushing syndrome and the diagnosis needs to be confirmed with laboratory and imaging tests.

How Is Cushing Syndrome Diagnosed?

Tell your doctor if you are taking any steroid medications. After taking a closer look at your history and performing a physical examination, your doctor will have a good idea as to what your diagnosis may be. 

The doctor will then order the following tests to confirm the diagnosis.

• Blood Cortisol levels: These are sensitive tests that detect the level of cortisol in your blood, which is understandably increased in a person with Cushing syndrome.
• You may be given a drug called dexamethasone before the test. Dexamethasone is a corticosteroid. In an otherwise healthy person, it will decrease cortisol levels due to negative feedback. If cortisol levels do not decrease, you may have Cushing syndrome. This is called a “dexamethasone suppression test”.
• Urine Test: For a urine cortisol test, you will be asked to collect your urine sample over a period of 24 hours. The sample is then submitted to the laboratory to analyze your cortisol levels.
• Saliva Test: In a healthy person, cortisol levels rise in the morning and drop very low in the night. However, Cushing syndrome patients have high cortisol levels at night. In this test, a sample of saliva is collected at midnight at home and delivered to the laboratory the next day.

These tests confirm the diagnosis of Cushing syndrome by detecting increased levels of cortisol. There are some other tests to determine the cause of Cushing syndrome, notably CT and MRI scans. These imaging techniques provide a full picture of your adrenal and pituitary glands. They can detect a growth or tumor of the pituitary or adrenal glands. These tests can determine the exact cause of Cushing syndrome.

Cushing Syndrome Treatment 

If you have Cushing syndrome because of long-term use of corticosteroid medication, your doctor may lower the dose gradually. They may stop the steroid drug altogether and prescribe a non-corticosteroid drug. This should be done under medical supervision because lowering the dose suddenly can be dangerous.

If the cause of Cushing syndrome is a tumor of the adrenal or pituitary gland, surgical excision of the tumor is the best option. Surgical excision of pituitary tumors is done by a neurosurgeon. Adrenal gland surgery is performed by a general surgeon. The latest minimally invasive surgical techniques with small incisions are used these days. After the surgery, the patient is required to take hormone replacement therapy.

If the surgeon is unable to remove the tumor completely or if the tumor is too small, radiation therapy may be done. It is also commonly given as an adjuvant to surgery.

If both radiotherapy and surgery fail, then medications may be given to decrease the production or counter the effects of excessive cortisol.

READ Primary Prevention of Hypertension

If left untreated, Cushing syndrome may lead to diabetes, hypertension, frequent bone fractures due to osteoporosis and serious infections. If you experience the typical symptoms of Cushing syndrome, you should contact your doctor to prevent serious and life-threatening complications.