Diagnosis

Your doctor will talk to you first about your medical history and your signs and symptoms. You may undergo some of the following tests:

• Blood test. Tests can measure your blood levels of sodium, potassium, cortisol and adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex to produce its hormones. A blood test can also measure antibodies associated with autoimmune Addison's disease.
• ACTH stimulation test. ACTH signals your adrenal glands to produce cortisol. This test measures the level of cortisol in your blood before and after an injection of synthetic ACTH.

• Insulin-induced hypoglycemia test. You may be given this test if doctors think you may have adrenal insufficiency as a result of pituitary disease (secondary adrenal insufficiency). The test involves checking your blood sugar (blood glucose) and cortisol levels after an injection of insulin. In healthy people, glucose levels fall and cortisol levels increase.

  In certain situations doctors may do alternative tests for secondary adrenal insufficiency, such as a low-dose ACTH stimulation test, prolonged ACTH stimulation test or glucagon stimulation test.

• Imaging tests. You may undergo a computerized tomography (CT) scan of your abdomen to check the size of your adrenal glands and look for other abnormalities. You may also undergo an MRI scan of your pituitary gland if testing indicates you might have secondary adrenal insufficiency.