What is Cushing Syndrome?
Cushing syndrome also known as Cushing’s syndrome or hypercortisolism is a collection of symptoms that develop as the result of very high levels of a hormone called cortisol in the body.
Cushing syndrome is caused by a noncancerous (benign) tumor of the pituitary gland, located at the base of the brain, secretes an excess amount of ACTH, which in turn stimulates the adrenal glands to make more cortisol This can happen for a variety of reasons. The most common cause is overuse of corticosteroid medications.
Causes of Cushing syndrome
Your adrenal glands produce cortisol. It helps with a number of your body’s functions, including:
- balancing the effects of insulin
- responding to stress
- regulating blood pressure and the cardiovascular system
- reducing the immune system’s inflammatory response
- converting carbohydrates, fats, and proteins into energy
Your body may produce high levels of cortisol for a variety of reasons, including:
- depression, panic disorders, or high levels of emotional stress
- high stress levels, including stress related to an acute illness, surgery, injury, or pregnancy, especially in the final trimester
- athletic training
The most common cause of Cushing syndrome is the use of corticosteroid medications, such as prednisone, in high doses for a long period. Doctors can prescribe these medications to prevent rejection of a transplanted organ. They also use them to treat inflammatory diseases, such as lupus and arthritis. High doses of injectable steroids for treatment of back pain can also cause this syndrome.
Lower dose steroids in the form of inhalants, such as those used for asthma, or creams, such as those prescribed for eczema, usually aren’t enough to cause Cushing syndrome.
Other causes include:
- a pituitary gland tumor in which the pituitary gland releases too much adrenocorticotropic hormone, which is also known as Cushing’s disease
- ectopic ACTH syndrome, which causes tumors that usually occur in the lung, pancreas, thyroid, or thymus gland
- an adrenal gland abnormality or tumor
Familial Cushing syndrome is another possible cause. Cushing syndrome isn’t typically inherited, but it’s possible to have an inherited tendency to develop tumors of the endocrine glands.
Symptoms of Cushing syndrome
The most common symptoms of this condition are:
- weight gain
- thinning skin that bruises easily
- skin injuries that are slow to heal
- increased thirst
- increased urination
- muscle weakness
- fatty deposits, especially in the midsection, the face (causing a round, moon-shaped face), and between the shoulders and the upper back (causing a buffalo hump)
- purple stretch marks on the breasts, arms, abdomen, and thighs
- glucose intolerance
- an increased incidence of infections
- bone loss
- high blood pressure
- a headache
- cognitive dysfunction
Women may also notice extra facial and body hair, as well as absent or irregular menstruation.
Men may also have:
- erectile dysfunction
- a loss of sexual interest
- decreased fertility
Children with this condition are generally obese and have a slower rate of growth.
Diagnosis of Cushing syndrome
Cushing syndrome can have many different causes. The diagnosis is made based on abnormal cortisol levels in the body. Your doctor will perform a physical examination and review your medical history and symptoms. They may also order laboratory tests, including:
- a 24-hour urinary free cortisol test
- midnight plasma cortisol and late-night salivary cortisol measurements
- a low-dose dexamethasone suppression test
After you receive the diagnosis of this condition, your doctor must still determine the cause of the excess cortisol production. Tests to help determine the cause may include a corticotropin-releasing hormone stimulation test and a high-dose dexamethasone suppression test. They may also order imaging studies, such as CT and MRI scans.
Treatment of Cushing Syndrome
Treatment will depend on the cause. Your doctor may prescribe a medication to help. Some medications decrease cortisol production in the adrenal glands or decrease ACTH production in the pituitary gland. Other medications block the effect of cortisol on your tissues.
If you use corticosteroids, a change in medication or dosage may be necessary. Don’t attempt to change the dosage yourself. You should do this under close medical supervision.
Tumors can be malignant, which means cancerous, or benign, which means noncancerous. Surgical removal may be necessary. Your doctor may also recommend radiation therapy or chemotherapy.
Complications of Cushing syndrome
If you don’t get treatment for it, Cushing syndrome can lead to:
- muscle loss and weakness
- high blood pressure
- type 2 diabetes
- bone loss
- bone fractures
- Cushing syndrome due to pituitary tumors can interfere with the production of other hormones.