17ohp2dpdexserplmcnc
A blood test that measures 17-hydroxyprogesterone levels after dexamethasone suppression to help diagnose adrenal gland disorders.
{"Measures 17-OHP hormone in blood 2 days after taking dexamethasone","Mainly used to screen for and diagnose congenital adrenal hyperplasia (CAH)","Helps doctors evaluate how your adrenal glands are functioning","A simple blood test performed at a laboratory","Results help differentiate between various adrenal conditions"}
Key facts at a glance
- LOINC
- 57549-8
- Short code
- 17-OHP
- Synonyms
- 17OHP 2D p Dex SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum Separator Tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 2
- Critical range
- — – 10 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Chemiluminescence Immunoassay (CLIA) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 80426
- SNOMED
- 31318003
- Specimen volume
- 1.0-2.0 mL serum minimum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days; Avoid repeated freeze-thaw cycles
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The 17-Hydroxyprogesterone (17-OHP) test measures the amount of a steroid hormone called 17-hydroxyprogesterone in your blood. This test is performed specifically after you have taken dexamethasone (a corticosteroid medication) for two days. Dexamethasone helps suppress normal adrenal hormone production, which allows doctors to see how your adrenal glands respond and identify certain disorders.
Why do I need this test?
Your doctor may order this test if they suspect you have a disorder affecting your adrenal glands, particularly congenital adrenal hyperplasia (CAH). CAH is a genetic condition that affects the adrenal glands' ability to produce cortisol and sometimes aldosterone. This test helps doctors confirm or rule out this condition and assess how well treatment is working if you have already been diagnosed.
How is the test performed?
First, you will take dexamethasone pills as prescribed by your doctor, usually for two days. On the third day, a healthcare professional will draw a blood sample from a vein in your arm. The blood sample is then sent to a laboratory for analysis. The actual blood draw only takes a few minutes and is generally well-tolerated.
How to prepare for the test
Follow your doctor's instructions exactly regarding dexamethasone dosage and timing. Do not stop taking any prescribed medications unless your doctor tells you to. Inform your doctor about all medications, supplements, or herbal products you are taking, as some substances may affect the test results. You may need to fast (not eat or drink anything except water) for a certain period before the blood test—ask your healthcare provider for specific instructions.
Understanding your results
Test results are measured in nanograms per deciliter (ng/dL) or other units depending on the laboratory. Normal results vary by age, sex, and whether you have CAH. Your doctor will interpret your results in context with your symptoms, medical history, and other test findings. Elevated 17-OHP levels after dexamethasone suppression may indicate certain forms of CAH or other adrenal disorders.
Reference range
Adults: <2.0 ng/mL (6.0 nmol/L); Children: Age-dependent; Post dexamethasone suppression: <1.0 ng/mL suggests adequate suppression; Reference ranges may vary by laboratory methodologyN/A
Patient must receive dexamethasone 0.5-2.0 mg every 6 hours for 2 days prior to specimen collection; specimen collected exactly 2 days after initial dexamethasone dose; inform laboratory of dexamethasone dose and timing
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is the 17-OHP test painful?
Are there any risks associated with this test?
How long does it take to get results?
Do I need to fast before the test?
What happens if my results are abnormal?
Sources
- 1
- 2
- 3
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 15, 2026. · Read our editorial policy