Methods for diagnosing adrenal gland disorders differ depending on the specific disorder. For example, the severe form of congenital adrenal hyperplasia (CAH) is most commonly identified during newborn screening.1 But pheochromocytoma is diagnosed using blood and urine tests.2
To diagnose an adrenal gland tumor, a health care provider may order one or more tests.3
- Blood and urine tests help measure the amount of adrenal hormones, which can detect a functional tumor.
- A computed tomography (CT or CAT) scan or a magnetic resonance imaging (MRI) scan may be useful in diagnosing an adrenal gland tumor and determining whether it is cancerous.
- A metaiodobenzylguanidine (MIBG) scan can detect a neuroendocrine tumor.
- An interventional radiologist can test the blood from the veins of each adrenal gland to identify tumors that CT or MRI scans can't pick up, or to determine if both glands have small masses (and thus both may require surgery).
If a health care provider suspects that a patient has Cushing's syndrome, he or she may order one or more of the three screening tests currently in use for this disorder.
- One of the tests screens for elevated cortisol levels in saliva.
- Another test looks for elevated cortisol levels in the urine over 24 hours.
- A third test checks to see if a synthetic (man-made) steroid, called dexamethasone (pronounced dek-suh-METH-uh-sohn), reduces cortisol production by the body.4
The most common way health care providers identify CAH in infants is through newborn screening. If the first screening test indicates that the infant may have CAH, the health care provider will order another blood test to confirm the diagnosis.
In some cases, female infants may have visible genital abnormalities that lead health care providers to suspect CAH as the cause. In these cases, health care providers will order an additional test to confirm the diagnosis.5 The milder form of CAH, when suspected, can also be diagnosed by the ACTH stimulation test (described below).
The first step in diagnosing pituitary tumors is a physical exam that includes checking neurologic responses, like reflexes and strength, and evaluation for signs of high hormone secretion, such as acne or unusual hair growth. A health care provider may also conduct a vision test to determine whether the growth of a pituitary tumor has affected sight or peripheral vision.
If results of this test lead the health care provider to suspect a pituitary tumor, he or she will order one or more tests of the patient's endocrine function.
To confirm the diagnosis, the health care provider may ask for a test of the patient's visual field (the area visible at a given instant without moving the eyes) or a magnetic resonance imaging scan of the patient's head.6
If a health care provider suspects a pheochromocytoma/paraganglioma, he or she may administer a blood or urine test. The test measures the levels of:
- Catecholamines (pronounced kat-i-KOL-uh-meens), hormones that increase the heart rate, blood pressure, rate of breathing, and amount of energy available to the body
- Metanephrines (pronounced met-uh-NEF-reens), molecules produced from the body breaking down catecholamines7
Typically, a blood test to measure cortisol levels and levels of adrenocorticotropic hormone (ACTH) is used to diagnose Addison's disease. A health care provider may also use an ACTH stimulation test, an hour-long test during which a person receives a synthetic (man-made) version of ACTH through an intravenous (IV) line. The health care provider compares blood levels of various hormones from before and after the ACTH is given. If cortisol levels are low, the person could have adrenal insufficiency and Addison's disease.8
If a health care provider suspects hyperaldosteronism, he or she may order blood and urine tests to check for high levels of aldosterone and low levels of potassium.
The health care provider also may order a computed tomography (called a CT or "cat") scan to determine whether there is a non-cancerous tumor or other abnormal growth of the adrenal glands.9
- Endocrine Society. (2010). Congenital adrenal hyperplasia fact sheet. Retrieved May 25, 2016, from http://www.hormone.org/questions-and-answers/2010/congenital-adrenal-hyperplasia
- National Adrenal Diseases Foundation. (n.d.). Pheochromocytoma: The facts you need to know. Retrieved May 25, 2016, from https://www.nadf.us/pheochromocytoma.html
- American Society of Clinical Oncology. (March, 2016). Adrenal gland tumor. Retrieved May 24, 2016, from http://www.cancer.net/cancer-types/adrenal-gland-tumor/diagnosis
- Cushing's Support and Research Foundation. (2003). Diagnostic testing for Cushing's syndrome. Retrieved May 25, 2016, from http://csrf.net/understanding-cushings/diagnostic-testing/
- Orphanet. (2012). Congenital adrenal hyperplasia. Retrieved May 25, 2016, from http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=GB&Expert=418
- New York Times Health Guide. (2012). Pituitary tumor. Retrieved June 1, 2012, from http://health.nytimes.com/health/guides/disease/pituitary-tumor/overview.html
- Columbia University Medical Center, Department of Surgery. (2011). Paraganglioma. Retrieved May 25, 2016, from http://www.columbiasurgery.org/adrenal/paraganglioma.html
- Society for Endocrinology. (2015). Addison's disease. Retrieved May 25, 2016, from http://www.yourhormones.info/endocrine-conditions/addisons-disease/
- National Library of Medicine. (2015). Hyperaldosteronism - primary and secondary. Retrieved May 25, 2016, from https://www.nlm.nih.gov/medlineplus/ency/article/000330.htm