What is Cushing’s syndrome?
Cushing’s syndrome is a hormonal illness caused by tall levels of the hormone cortisol in your body. It is also known as hypercortisolism. Cortisol comes from the adrenal glands, which are located on top of the kidneys. Help your body to:
- Maintain blood pressure
- Regulate blood sugar
- Reduce inflammation
- Convert the food you eat into energy
But when you have too much cortisol, it can disrupt the other systems in your body.
Most cases of Cushing’s syndrome can be cured, although it may take some time for symptoms to go away.
The condition is more communal in women than men. It is most often seen in people ages 25 to 40.
Types of Cushing’s syndrome
There are two types of Cushing’s syndrome:
Exogenous Cushing’s syndrome
Exogenous Cushing’s syndrome occurs when the cause comes from something outside of the body’s function.
It is often the result of long-term use of high doses of corticosteroids, also known as glucocorticoids. They are similar to cortisol.
People with rheumatoid arthritis, lupus, asthma, and organ transplant recipients may need high doses of these medications.
Injectable corticosteroids, treatment for joint pain, back pain, and bursitis, can also cause Cushing’s syndrome.
Steroid medications that do not appear to increase the risk of Cushing’s syndrome include:
- Steroid creams, a treatment option for eczema
- Inhaled steroids, a treatment for asthma
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) notes that more than 10 million individuals in the United States use glucocorticoid medications each year, but it is unclear how many develop symptoms of Cushing’s syndrome.
Endogenous Cushing’s syndrome
Endogenous Cushing’s syndrome occurs when the cause comes from inside the body, for example, when the adrenal glands make too much cortisol.
Cushing’s disease is an example of this.
Similar symptoms can also result from tumors of the adrenal gland or from a benign or malignant tumor in the pancreas, thyroid, thymus, or lung.
These can also result in an overproduction of cortisol.
Signs and symptoms of Cushing’s syndrome:
- Weight gain in the face (moon face)
- Weight gain above the clavicle (supraclavicular fat pad)
- Weight gain in the back of the neck (buffalo hump)
- Skin changes with easy bruising of the extremities and development of violaceous stretch marks (stretch marks), especially in the abdomen or armpit region
- Red and round face (plethora)
- Central obesity with weight gain centered on the chest and abdomen with thin arms and legs
- Excessive hair growth (hirsutism) on the face, neck, chest, abdomen, and thighs
- Female baldness
- Generalized weakness and fatigue
- Blurry vision
- Muscular weakness
- Menstrual disorders in women (amenorrhea)
- Decreased fertility and/or sexual desire (libido)
- Poor wound healing
- Mellitus diabetes
- Severe depression
- Extreme mood swings
Causes of Cushing’s syndrome
A benign pituitary tumor (adenoma)
This is the most common cause of CS. Nearly 75 out of 100 to 85 out of 100 cases of Cushing’s syndrome are of this type. Corticotropin (CRH) is normally produced by the pituitary gland. It is a hormone that stimulates the adrenal gland to release cortisol, especially during times of stress. A pituitary tumor causes too much corticotropin (also called ACTH) to be made. ACTH is a kind of pituitary control switch that manages the growth and activity of the adrenal glands. Too much corticotropin causes the adrenal gland to type too much cortisol. Too much cortisol can cause SC.
This major cause of CS is when a tumor is found in the adrenal gland. The tumor may or may not be cancerous.
Ectopic (abnormal) ACTH
This is when CS is caused by ACTH-producing tumors in other organs. For example, tumors found in the chest in the lung or thymus can produce ACTH.
Steroids used in high doses and for long periods can cause CS. For example, the use of prednisone.
It is normal to find high levels of cortisol in the body due to stress. This does not lead to Cushing’s syndrome.
In very rare cases, there is a hereditary link to an endocrine tumor that could cause SC. Most cases of SC are not transmitted.
Risk factors for Cushing’s syndrome
Why is not fully understood yet, but Cushing’s syndrome is diagnosed more often in women than men. It also appears to be more common in the 25-40 age group.
Other factors that can increase a person’s risk for Cushing’s syndrome include:
- Obesity, type 2 diabetes, and poorly regulated blood glucose levels (blood sugar and hypertension)
- Taking corticosteroid medications (long-term use)
- Pituitary gland tumors
- Primary disease of the adrenal glands or benign nodular enlargement of the adrenal glands
- An ACTH-secreting ectopic tumor (a growth that forms in an organ of the body that does not normally produce ACTH, a hormone that regulates cortisol levels)
Diagnosis of Cushing’s syndrome
In its early stages, adrenal insufficiency can be difficult to diagnose, as symptoms appear slowly. Your healthcare professional may suspect this after reviewing your medical history and symptoms. The next step is a blood test to see if your cortisol levels are too low and to help find the cause.
ACTH stimulation test
The ACTH stimulation test is the test most often used to diagnose adrenal insufficiency. In this test, a healthcare professional will give you an intravenous (IV) injection of artificial ACTH, which is similar to the ACTH your body makes. Your healthcare professional will take samples of your blood before and 30 minutes or 60 minutes after the injection. Cortisol levels in your blood samples are measured in a laboratory.
The normal response after an ACTH injection is an increase in cortisol levels in the blood. Persons with Addison’s disease and most people who have had secondary adrenal insufficiency for a long time have little or no intensification in cortisol levels. The adrenal glands may be too damaged to respond to ACTH.
Insulin tolerance test
If the results of the ACTH stimulation test are unclear or your doctor suspects a problem with the pituitary, you may have an insulin tolerance test (ITT). A healthcare professional will give you an intravenous injection of the hormone insulin, which lowers your blood glucose levels. The dose is high enough to cause hypoglycemia, which happens when your blood glucose equal drops too low.
CRH stimulation test
The CRH stimulation test is another option to help identify secondary insufficiency if the ACTH test results are unclear. This test can also differentiate secondary from tertiary adrenal insufficiency.
Antibody blood test
A blood test can find antibodies that are present in autoimmune Addison’s disease. Antibodies are proteins made by your immune system to protect your body from bacteria or viruses. In autoimmune Addison’s disease, antibodies mistakenly attack the adrenal glands. Most, but not all, persons with autoimmune Addison’s disease have these antibodies. If the test shows antibodies, no further testing is necessary.
Computed tomography (CT)
NIH external link CT scans use a combination of X-rays and computer technology to create images of your organs and other internal structures. A CT scan of the abdomen can find changes in the adrenal glands. In autoimmune Addison’s disease, the glands are small or normal in size and have no other visible abnormalities.
Magnetic resonance imaging (MRI)
MRI machines use radio waves and magnets to create detailed images of your internal organs and soft tissues without using X-rays. An MRI scan can look for changes in the pituitary and hypothalamus, such as large, non-cancerous pituitary tumors.
Treatment for Cushing’s syndrome
The overall goal of treating Cushing’s syndrome is to lower the levels of cortisol in your body. This can be done in several ways. The treatment you receive will depend on the cause of your condition.
Your healthcare provider can prescribe medicine to help control cortisol levels. Some medications decrease the production of cortisol in the adrenal glands or decrease the production of ACTH in the pituitary gland. Other medicines block the effect of cortisol on your tissues.
- Ketoconazole (Nizoral)
- Mitotane (Lysodren)
- Metyrapone (Methopyrone)
- Pasireotide (Signifor)
- Mifepristone (Korlym, Mifeprex) in people with type 2 diabetes or glucose intolerance
If you use corticosteroids, a change in medication or dosage may be necessary. Do not try to change the dose yourself. You must do this under close medical supervision.
Tumors can be malignant, which means cancerous, or benign, which means non-cancerous. If your condition is caused by a tumor, your healthcare provider may want to surgically remove it. If the tumor cannot be unconcerned, your healthcare provider may also recommend radiation therapy or chemotherapy.
Without treatment, complications of Cushing syndrome can include:
- Bone loss (osteoporosis), which can lead to unusual bone fractures, such as broken ribs and broken bones in the feet.
- High blood pressure (hypertension)
- Type 2 diabetes
- Frequent or unusual infections
- Loss of muscle mass and strength