Tests for Cushings Disease

Cushing's disease is the body's response to excess cortisol production in the body. A person with Cushing's disease shows excess weight in the face, neck and mid region of the body. Development of the disease is rare and most commonly found in adults age 20 to 50 years. People suffering from glucose control diseases are at a higher risk of developing Cushing's disease.

Identification

• Cushing disease occurs when there is a disorder in the adrenal glands and too much cortisol is secreted. The excess cortisol hormone is carried in the blood and affects other cells in the body.

Symptoms

• The most common and first recognizable symptom of Cushing's disease is a sudden weight gain in patients. Muscle weakness along with bruising, rounding of the facial area and hypertension accompany the weight gain. Severe fatigue and an increase in thirst and urination will follow. A person with the disease will also be irritable and have anxiety and depression.

Cause

• Cushing's disease occurs when the body is exposed to an excess in cortisol for too long a period. Excess cortisol is produced when the pituitary gland is signaled to release a hormone that stimulates the adrenal gland. When the adrenal gland receives hormone stimulation, cortisol is released into the blood. People who take glucocorticoids steroid hormones for asthma, lupus or arthritis may develop Cushing's disease as the drug has the same effect as cortisol on the body.

Tests

• In order to accurately diagnose Cushing's disease, several tests must be completed. A 24-hour test of the urine requires that urine be collected several times over the period to test the levels of cortisol. A midnight plasma test requires a 48 hour hospital stay to monitor cortisol levels in the blood. A normal person will have a decrease in levels during sleep times, but not if Cushing's disease is present. The hospital stay is used to monitor levels and reduce stress in the patient as it increases cortisol production. A two-day dexamethasone test involves injecting a low dose of dexamethasone every six hours for two days. The urine is tested for cortisol levels. The dexamethasone is a synthetic glucocorticoid that stimulates a reduction of cortisol production. A person with Cushing's disease will not respond to the injection.

Treatment

• Treatment for Cushing's disease is based on the cause. People using a high dose of glucocorticoids may require a reduction or change in medication. Treatment for other causes of the disease is varied based on the specific symptoms and the body's reaction to cortisol.