Understanding Your Laboratory Test: What It Is, Why It Is Done, and What to Expect
This test measures 17-hydroxyprogesterone levels in your blood 30 minutes after receiving an injection of corticotropin (ACTH) to help diagnose adrenal gland disorders.
{"The test checks how your adrenal glands respond to ACTH stimulation","It primarily helps diagnose Congenital Adrenal Hyperplasia (CAH)","A blood sample is taken before and 30 minutes after ACTH injection","Results help doctors distinguish between different adrenal disorders","The test is usually performed in the morning after overnight fasting"}
Key facts at a glance
- LOINC
- 55469-1
- Short code
- 17-OHP ACTH stim
- Synonyms
- 17OHP 30M p ACTH SerPl-sCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 15
- Ref high
- 30
- Critical range
- — – 50 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Immunoassay (Chemiluminescence or ELISA)
- CPT
- 82533
- SNOMED
- 31316005
- Specimen volume
- 1-2 mL serum minimum
- Stability
- Refrigerated (2-8°C): up to 7 days; Frozen (-20°C or below): up to 30 days; Avoid repeated freeze-thaw cycles
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 40
- TAT
- 24–72 hours
- Order
- routine
This test is a medical evaluation that helps your healthcare provider gather important information about your health. It measures or checks specific markers in your body so your care team can understand how well your organs and systems are functioning and identify any conditions that may need further attention or treatment.
The 17-Hydroxyprogesterone (17-OHP) ACTH stimulation test is a specialized blood test that measures how your adrenal glands respond to corticotropin (ACTH), a hormone produced by the pituitary gland. After a small injection of synthetic ACTH, blood samples are taken to measure the change in 17-hydroxyprogesterone levels. This helps doctors evaluate whether your adrenal glands are functioning properly.
Your doctor may order this test to help diagnose a medical condition, monitor an illness you already have, or check how well a current treatment is working. The results can also be used to screen for early signs of disease, guide decisions about your care, and give you and your healthcare team a clearer picture of your overall health.
This test is primarily used to diagnose and differentiate adrenal gland disorders, especially Congenital Adrenal Hyperplasia (CAH), a genetic condition affecting adrenal hormone production. It can also help distinguish between adrenal insufficiency and other conditions causing similar symptoms like fatigue, weight loss, or hormonal imbalances.
The test is usually performed in a doctor's office, clinic, or laboratory. Depending on the type of test, a small sample such as blood, urine, or tissue may be collected, or a special machine may be used to examine a part of your body. The procedure is typically quick, and a trained professional will explain each step and help keep you comfortable.
The test typically involves: 1) A baseline blood sample is taken, 2) An injection of synthetic ACTH is given, 3) Another blood sample is collected 30 minutes later. The procedure usually takes about 1-2 hours. You may be asked to fast overnight and avoid certain medications before the test.
Most patients go through this test without any problems. If a sample is collected, you may feel slight discomfort, bruising, or minor soreness at the site, which usually goes away within a day or two. Serious complications are rare, but contact your healthcare provider if you notice unusual pain, swelling, bleeding, or signs of infection.
The risks are minimal and include minor bleeding, bruising, or soreness at the injection site. Some people may experience temporary flushing or mild discomfort from the ACTH injection. Serious allergic reactions are rare.
Reference range
Non-classic CAH: 17-OHP 30 min post-ACTH typically 15-30 nmol/L; Classic CAH (21-hydroxylase deficiency): 17-OHP 30 min post-ACTH usually >30 nmol/L; Normal response: <15 nmol/L at 30 minutes post-ACTHN/A
Patient should be in basal state (morning sample preferred). Synthetic ACTH (cosyntropin) 250 mcg is administered intravenously or intramuscularly. Blood sample is drawn 30 minutes after ACTH administration. Continue any prescribed glucocorticoids unless instructed otherwise by physician.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose Congenital Adrenal Hyperplasia (CAH), a group of genetic disorders affecting adrenal hormone production. It helps differentiate between classic and non-classic CAH. The test can also aid in diagnosing adrenal insufficiency, Cushing's syndrome, and certain adrenal tumors. In children, it helps evaluate early or ambiguous genitalia and premature puberty. In adults, it assists in evaluating hormonal imbalances, infertility issues, and adrenal dysfunction.
Frequently asked questions
How should I prepare for the test?
What do abnormal results mean?
How long does it take to get results?
Is this test safe for children?
Sources
- 1
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy