Understanding Your Laboratory Test: A Complete Patient Guide

This test is a laboratory procedure that helps your healthcare provider learn important information about your health. By analyzing a sample, usually blood, urine, or another body fluid, the test can show how well certain organs are working and whether there are any signs of illness or abnormal changes in your body.

The androstenedione test measures the amount of androstenedione, a hormone produced by the adrenal glands, ovaries (in women), and testes (in men), in your blood. This specific test is performed one hour after receiving a stimulating agent (challenge), typically synthetic ACTH (cosyntropin), which prompts your adrenal glands to release hormones. Comparing baseline and post-challenge levels helps doctors understand how well your adrenal glands are functioning.

Your doctor may order this test to help diagnose a medical condition, check how well a treatment is working, monitor a chronic disease over time, or screen for problems before symptoms appear. It is often part of a routine checkup or used to investigate symptoms such as fatigue, pain, fever, or unexplained changes in your health.

Your doctor may order this test if you have symptoms suggesting a hormonal imbalance, such as early puberty, irregular periods, excess hair growth (hirsutism), acne, or infertility. It helps diagnose conditions including congenital adrenal hyperplasia (CAH), adrenal tumors, polycystic ovary syndrome (PCOS), and adrenal insufficiency. The test is also used to evaluate adrenal gland function before and after treatment for these conditions.

Preparation depends on the type of test your provider ordered. You may be asked to fast for 8 to 12 hours beforehand, which means avoiding food and drinks except water. Tell your care team about all medications, vitamins, and supplements you take, because some can affect the results. Wear comfortable clothing with sleeves that roll up easily and drink plenty of water unless instructed otherwise.

Follow these preparation guidelines: Fast for 8-12 hours before the test unless instructed otherwise by your doctor. Inform your doctor about all medications you're taking, especially corticosteroids, hormonal contraceptives, or other hormone therapies, as these may affect results. Tell your doctor if you are pregnant or have any recent illnesses. Rest and avoid strenuous exercise before the test. Your doctor will provide specific instructions about whether to continue or stop certain medications before the test.

Most laboratory tests involve a simple blood draw performed by a trained phlebotomist or nurse. A small needle is inserted into a vein, usually in your arm, and a sample is collected into a tube. The process typically takes only a few minutes. For other tests, you may be asked to provide a urine, saliva, or stool sample instead. After collection, the sample is sent to a laboratory for analysis.

The test involves two blood draws: 1) A baseline sample is taken to measure your initial androstenedione level. 2) You receive a synthetic hormone (usually cosyntropin/ACTH) through an injection or IV. 3) Exactly one hour later, a second blood sample is drawn. The entire procedure typically takes 1-2 hours. The blood samples are sent to a laboratory for analysis.

The risks are very small. You may experience brief discomfort, minor bruising, or slight soreness at the needle site. Some people feel lightheaded or dizzy during a blood draw, so let the staff know if this happens. Serious complications, such as infection or excessive bleeding, are rare. The benefits of getting accurate results usually far outweigh these minor risks.

The risks are minimal and similar to routine blood tests, including slight pain or bruising at the injection site, lightheadedness, and rare risk of infection. The challenge medication may cause temporary flushing, headache, nausea, or rapid heartbeat. These side effects are usually mild and subside quickly. Serious allergic reactions to the challenge medication are rare but possible.

Your results are usually compared with a reference range, which shows the levels typically seen in healthy people. A result outside this range does not always mean you have a disease, and normal results do not always rule out every condition. Your healthcare provider will explain what your numbers mean, whether follow-up testing is needed, and what the next steps are for your care. Always review your results together with your provider rather than interpreting them on your own.

Results show your androstenedione levels at baseline and one hour after stimulation. Normal responses vary by age, sex, and laboratory reference ranges. An exaggerated increase may indicate conditions like CAH or adrenal tumors. A blunted or absent response suggests adrenal insufficiency. Your doctor will interpret your results in context with your symptoms, physical exam, and other test results. Abnormal results do not always mean you have a serious condition—your healthcare provider will discuss what your specific results mean for you.