Understanding Your Medical Test: A Complete Patient Guide to What It Is, How It Is Performed, and What Your Results Mean

This test is a medical procedure that helps your doctor check how your body is working, look for signs of illness, or confirm a diagnosis. Learning what the test measures before your appointment can help you feel more informed, comfortable, and confident about your care.

The androstenedione test measures the level of androstenedione in your blood. Androstenedione is a hormone produced by your adrenal glands, ovaries (in women), and to a lesser extent by the testes (in men). This particular test is performed after stimulating your adrenal glands with adrenocorticotropic hormone (ACTH), also known as the corticotropin stimulation test.

How Is the Test Performed? Your test is performed by a trained member of your care team, and the exact steps depend on the type of test your doctor ordered. Some tests use a small blood sample drawn from a vein in your arm, while others rely on imaging equipment or a simple bedside assessment.

The test typically involves the following steps: First, a baseline blood sample is taken to measure your initial androstenedione level. Then, you will receive an injection of 250 micrograms of synthetic ACTH (cortrosyn) into your muscle. One hour after the injection, another blood sample is collected. The difference between the two measurements shows how your adrenal glands respond to stimulation.

Why Might I Need This Test? Your doctor may order this test to investigate symptoms you are having, monitor an ongoing condition, screen for disease before symptoms appear, or see how well a current treatment is working so your care team can make well-informed decisions.

Your doctor may order this test if you show symptoms of adrenal gland dysfunction, such as abnormal hair growth (hirsutism), menstrual irregularities, early puberty, or signs of adrenal insufficiency. It is commonly used to diagnose and differentiate between conditions like congenital adrenal hyperplasia (CAH), adrenal tumors, and other adrenal disorders.

How Should I Prepare? Preparation depends on the type of test, so follow the specific instructions from your provider. You may be asked to fast for several hours, avoid certain medications or supplements, or drink extra water. Always mention any allergies, medications, or health conditions beforehand.

Follow these preparation guidelines: Fast for 8-12 hours before the test (usually overnight). Inform your doctor about all medications you are taking, especially hormone medications, steroids, or birth control pills. The test is typically performed in the morning since hormone levels follow a daily rhythm. Wear comfortable clothing that allows easy access to your arm for blood draws.

What Do the Results Mean? Your results show whether your values fall within the expected reference range. Results in the normal range can be reassuring, while values outside that range may point to a condition that needs closer evaluation. Your provider will explain your results and discuss any next steps with you.

Normal androstenedione response to ACTH stimulation varies by age and sex. An elevated response may indicate conditions like congenital adrenal hyperplasia or adrenal tumors. A blunted or absent response may suggest adrenal insufficiency (Addison's disease) or pituitary gland problems. Your doctor will interpret your results in context with other clinical findings and tests.

Are There Any Risks? Most tests carry very few risks. You may feel brief discomfort, or notice mild bruising or minor bleeding where a sample was taken, but serious complications are rare. Contact your provider if you have concerns or notice unusual symptoms such as swelling, persistent pain, or fever after the test.

The risks are minimal and similar to routine blood tests. You may experience slight pain or bruising at the injection site. Some people may feel lightheaded during or after the blood draw. The ACTH injection may cause temporary flushing or mild discomfort. Serious complications are rare.