Understanding Your Medical Test: What It Is, How It's Done, and What Your Results Mean

What is this test and what does it check for?

The androstenedione challenge test measures the level of androstenedione in your blood. Androstenedione is a hormone produced by the adrenal glands (above your kidneys), as well as in the ovaries in women and testes in men. It serves as a building block for other hormones like testosterone and estrogen. This test is performed after a 'challenge'—typically an injection of ACTH (adrenocorticotropic hormone)—to see how your adrenal glands respond to stimulation.

How is this test performed, and what can I expect during the procedure?

The test involves two blood draws: one before the challenge and another 30 minutes after. For the challenge, a healthcare provider will inject a synthetic form of ACTH (cosyntropin) into your muscle or vein. This stimulates your adrenal glands to produce hormones. Both blood samples are then sent to a laboratory to measure androstenedione levels and assess how much they increased after stimulation.

Why might my doctor recommend this test for me?

Your doctor may order this test if you have symptoms of excess androgens (male hormones), such as irregular menstrual periods, excess hair growth (hirsutism), acne, or male-pattern baldness in women. It helps determine whether these symptoms are due to adrenal gland problems or conditions affecting the ovaries or testes. The test is also used to evaluate adrenal gland function and diagnose conditions like congenital adrenal hyperplasia, adrenal tumors, or polycystic ovary syndrome (PCOS).

How should I prepare for this test before my appointment?

Follow your healthcare provider's instructions carefully. You may need to fast (not eat or drink anything except water) for 8-12 hours before the test. Certain medications, such as corticosteroids, hormonal contraceptives, or androgen-containing drugs, may affect results—inform your doctor about all medications and supplements you take. The test is usually performed in the morning since hormone levels can vary with your circadian rhythm.

What do my test results mean, and what happens next?

Results are interpreted by comparing your baseline (pre-challenge) and post-challenge androstenedione levels. A normal response shows a significant increase in androstenedione after stimulation. An exaggerated response may suggest adrenal hyperplasia, adrenal tumor, or certain ovarian conditions. A blunted or absent response may indicate adrenal insufficiency (Addison's disease). Your doctor will consider your symptoms, medical history, and other test results when interpreting your findings.