Your Laboratory Test: What It Is, Why You Need It, and How to Prepare
This blood test measures 17-hydroxyprogesterone levels 30 minutes after a hormone stimulation challenge to help diagnose adrenal gland disorders such as congenital adrenal hyperplasia.
{"Measures how your adrenal glands respond to stimulation","Helps diagnose congenital adrenal hyperplasia (CAH) and other adrenal disorders","Requires blood samples taken before and 30 minutes after the challenge","Results indicate whether your body produces excess or deficient hormones","Important for both children and adults with hormone-related symptoms"}
Key facts at a glance
- LOINC
- 53141-8
- Short code
- 17-OHP-STIM
- Synonyms
- 17OHP 30M p chal SerPl-sCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 30
- Ref high
- 60
- Critical range
- — – 100 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Immunoassay (Chemiluminescence or ELISA)
- CPT
- 82533
- SNOMED
- 313269007
- Specimen volume
- 1-2 mL serum minimum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 40
- TAT
- 24–72 hours
- Order
- routine
What is this test? This test is a laboratory analysis performed on a sample of your blood, urine, or other body fluid to measure specific substances and help your doctor evaluate your overall health or check for certain medical conditions.
The 17-Hydroxyprogesterone (17-OHP) Challenge Test is a diagnostic blood test that measures the level of 17-hydroxyprogesterone in your blood 30 minutes after receiving a hormone stimulation challenge. This test evaluates how well your adrenal glands are functioning and helps detect certain hormonal disorders.
Why do I need this test? Your doctor may order this test to help diagnose a medical condition, monitor an ongoing health problem, screen for disease before symptoms appear, or check how well a current treatment is working for you.
Your doctor may order this test if you or your child have symptoms suggesting a adrenal gland disorder, such as: early puberty, irregular periods, excessive hair growth, ambiguous genitalia in newborns, or difficulty handling stress. The test is particularly important for diagnosing congenital adrenal hyperplasia (CAH), a genetic condition affecting hormone production.
How should I prepare? Preparation depends on the specific test ordered. You may be asked to fast for 8 to 12 hours, avoid certain foods, drinks, or medications, and drink plenty of water. Always follow the exact instructions your healthcare provider gives you.
Follow your doctor's instructions carefully. You may need to fast (not eat or drink anything except water) for 8-12 hours before the test. Inform your doctor about all medications you're taking, as some drugs can affect hormone levels. For children, the challenge substance (usually synthetic ACTH) is given as an injection, so follow any specific preparation instructions provided by your healthcare team.
What happens during the test? A trained healthcare professional will collect a small sample, usually by drawing blood from a vein in your arm with a thin needle. The procedure typically takes only a few minutes, and you may feel a brief pinch or slight discomfort at the needle site.
The test typically involves two blood samples: 1) A baseline sample taken before the challenge, and 2) A second sample taken exactly 30 minutes after receiving an injection of synthetic ACTH (adrenocorticotropic hormone). The challenge stimulates your adrenal glands to produce hormones, and the blood samples measure how they respond. The entire procedure usually takes about 1-2 hours.
What do the results mean? Your results are compared with established reference ranges. Values outside the normal range may suggest a condition that needs further evaluation, but only your healthcare provider can interpret your results accurately in the context of your overall health.
Your results will show 17-OHP levels measured in the blood. Elevated levels after the challenge suggest conditions like congenital adrenal hyperplasia or other adrenal disorders. Normal or appropriately rising levels suggest normal adrenal function. Your doctor will interpret these results in context with your symptoms, medical history, and other test results.
Reference range
30 minutes post-ACTH stimulation: Normal response <30 nmol/L (900 ng/dL); Indeterminate 30-60 nmol/L (900-1800 ng/dL); Elevated/Consistent with CAH >60 nmol/L (>1800 ng/dL)N/A
No fasting required. Schedule ACTH (cosyntropin) stimulation test in morning. Patient should inform physician of current medications, especially corticosteroids or hormonal contraceptives. Baseline sample collected, then ACTH administered intramuscularly or intravenously, with second sample collected exactly 30 minutes post-administration.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose and evaluate congenital adrenal hyperplasia (CAH), a group of genetic disorders affecting the adrenal glands' ability to produce cortisol and sometimes aldosterone. It helps distinguish between adrenal and gonadal sources of excess hormones. The test is also valuable for identifying other adrenal enzyme deficiencies, evaluating adrenal insufficiency, and guiding treatment decisions for patients with hormone disorders. Early diagnosis of CAH is crucial for proper management and preventing complications.
Frequently asked questions
Is this test painful?
How long does it take to get results?
Are there any risks or side effects?
Can this test be done on newborns?
What happens after the test?
Sources
- 1
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Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
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 10, 2026. · Read our editorial policy