The adrenal glands are located on top of each kidney. Like other endocrine glands, they function as hormone producers. Each adrenal gland is composed of an outer cortex and inner medulla. Different regions of the adrenal glands produce different hormones. The cortex secretes corticoids and sex hormones, while the medulla produces epinephrine and norepinephrine. Adrenal gland disorders typically cause an alteration in the amount of hormones produced by the gland.
Types
Tests for adrenal gland function can be conducted in a number of different ways. The initial approach is usually to begin with routine blood and urine tests, then proceed to specific blood and urine tests designed to address known adrenal disorders.
Imaging tests such as computerized tomography, or CT scans, and magnetic resonance imaging, or MRI, can be ordered to assess the size and condition of the adrenal gland.
Tests for congenital adrenal disorders can be administered even before birth, via amniocentesis and chorionic villus sampling, according to MayoClinic.com. Tests for adrenal gland function can be conducted in a number of different ways. The initially approach is usually to conduct routine blood and urine tests, then specific blood and urine tests designed to address known adrenal disorders.
Function
Most adrenal gland tests function by evaluating the levels of various adrenal hormones in the body.
Cortisol levels, for example, can be assessed via a blood test, according to the "New York Times". A cortisol level lower than 6 micrograms per deciliter of blood may indicate Addison's disease or hypopituitarism. Cortisol levels above 23 micrograms per deciliter can be a sign of adrenal tumor or Cushing's syndrome.
Some blood tests involve the administration of synthetic hormones in order to evaluate the adrenal gland's response. Adrenocorticotrophic hormone, or ACTH, is excreted by the pituitary gland to stimulate adrenal hormone production. In an ACTH stimulation test, synthetic ACTH is injected into the blood stream, and during the hour that follows numerous blood samples are drawn to check the adrenal gland's response.
Imaging techniques such as CT scans and MRI can be used to determine the presence of tumors growing within the gland, according to the National Adrenal Diseases Foundation.
Considerations
Blood and urine tests are relatively risk free, as long as trained professionals administer the tests in sanitary conditions. "The New York Times" notes that some patients have smaller blood vessels that may make drawing blood more difficult. Fainting, excessive bleeding and hematoma are sometimes associated with having blood drawn.
CT and MRI scans may cause some anxiety in the claustrophobic but cause no known long-term complications.
Complications
Adrenal gland disorders can be life altering. Women with excessive production of adrenal sex hormones can develop masculine features such as facial hair and deepening of the voice.
Cardiovascular complications can ensue when adrenal disorders alter the levels of aldosterone, a hormone that regulates sodium levels in the blood.
Fat redistribution occurs in some adrenal disorders, causing a moon-faced appearance with a hump between the shoulder blades that can significantly impact the patient's self esteem and well-being.
Prognosis
Adrenal disorders involving deficient hormone production can sometimes require lifelong dependency on hormone replacement therapy, though MayoClinic.com notes that congenital adrenal disorders may result in a smaller stature when the child grows to adulthood.
Adrenal tumors can be asymptomatic, but those greater than 3 cm should be monitored via CT imaging, as increased growth indicates a potential for malignancy.
References
- Adrenal Diseases Foundation: What Should be Done About Adrenal Tumor?
- National Institutes of Health: Adrenocorticotrphic Hormone
- MayoClinic.com: Congenital Adrenal Hyperplasia: Tests and Diagnosis
- New York Times: Cortisol Levels
- The Human Body in Health and Disease; Gary Thibodeau, PhD and Kevin Patton, PhD; 2002
