Understanding Your Medical Test: What It Is, Why It Is Done, and How to Prepare

This test is a medical procedure that helps your health care provider learn more about how your body is working. It can be used to check for a health problem, confirm a diagnosis, or monitor a condition you already have over time.

This test measures the amount of ACTH (adrenocorticotropic hormone, also called corticotropin) in your blood. ACTH is produced by the pituitary gland, a small pea-sized gland at the base of your brain. The test is performed 30 minutes before you receive a glucagon injection as part of a stimulation test.

Your provider may order this test to find the cause of symptoms you are having, to screen for disease before symptoms appear, or to see how well a treatment is working. The results help guide important decisions about your ongoing care.

This test is part of a glucagon stimulation test, which evaluates how well your pituitary and adrenal glands work. The test helps doctors diagnose conditions such as Addison's disease (adrenal insufficiency), Cushing's syndrome (excessive cortisol), and pituitary gland disorders. Your healthcare provider may order this test if you have symptoms like fatigue, weight changes, low blood pressure, or hormonal imbalances.

Preparation depends on the type of test being done. You may be asked to fast for a certain number of hours, avoid certain foods or medicines, or drink extra water. Tell your provider about all medicines, vitamins, and supplements you take, and ask whether you should keep taking them.

Follow your healthcare provider's instructions carefully. You may need to fast (not eat or drink) for a certain period before the test. Inform your doctor about all medications you are taking, as some medicines can affect ACTH levels. These may include steroids, birth control pills, and certain psychiatric medications. Wear comfortable clothing with sleeves that can be easily rolled up for blood draw.

During the test, a trained member of your health care team will explain each step before it happens. Depending on the test, a small sample of blood, urine, or other tissue may be collected, or a machine may be used to take pictures or measurements of your body. Most tests take only a short time to complete.

A healthcare professional will draw a blood sample from a vein in your arm. This sample is taken 30 minutes before you receive the glucagon injection. The blood draw only takes a few minutes and may cause slight discomfort or bruising at the injection site. After the blood sample is collected, you will receive the glucagon injection as part of the stimulation test, and additional blood samples may be taken at other time points.

Most tests are very safe, but some carry small risks, such as brief pain, bruising, or bleeding where a needle was inserted, or mild discomfort from the procedure itself. Serious problems are rare. Call your provider if you notice unusual pain, swelling, fever, or bleeding after the test is done.

The risks of this test are minimal. You may experience slight pain, bruising, or bleeding at the blood draw site. In rare cases, fainting or infection may occur. The glucagon injection may cause temporary side effects such as nausea, vomiting, or flushing. Contact your healthcare provider if you experience any unusual symptoms.