A health care professional will draw your blood at the beginning of the test and again every half hour during the next 2 hours. Hypoglycemia causes physical stress, which normally triggers the pituitary to make more ACTH. The dose is high enough to cause hypoglycemia, which occurs when your blood glucose level drops too low. A health care professional will give you an IV injection of the hormone insulin, which lowers your levels of blood glucose.

If the results of the ACTH stimulation test aren’t clear or your doctor suspects a problem in the pituitary, you may have an insulin tolerance test (ITT). The ACTH test may not be accurate in people who have had secondary adrenal insufficiency for a shorter time because their adrenal glands have not yet shrunk and can still respond to ACTH. The adrenal glands may be too damaged to respond to ACTH. People with Addison’s disease and most people who have had secondary adrenal insufficiency for a long time have little or no increase in cortisol levels. The normal response after an ACTH injection is a rise in blood cortisol levels. Blood tests can find out if your cortisol levels are too low. The cortisol levels in your blood samples are measured in a lab. Your health care professional will take samples of your blood before and 30 minutes or 60 minutes after the injection. In this test, a health care professional will give you an intravenous (IV) injection of man-made ACTH, which is just like the ACTH your body makes. The ACTH stimulation test is the test used most often to diagnose adrenal insufficiency. The next step is blood testing to see if your cortisol levels are too low and to help find the cause. Your health care professional may suspect it after reviewing your medical history and symptoms. In its early stages, adrenal insufficiency can be hard to diagnose since symptoms come on slowly.

Your doctor will review your symptoms and run tests to confirm that your cortisol levels are low. How do doctors diagnose adrenal insufficiency?

Adrenal gland malfunction