5-Alpha-Tetrahydrocortisol/Tetrahydrocortisol Ratio, 24-Hour Urine
A 24-hour urine test that measures the balance of 5-alpha-tetrahydrocortisol relative to total tetrahydrocortisol, providing information about steroid metabolism.
["This steroid-metabolism ratio may help evaluate unusual cortisol breakdown or androgen-related enzyme activity, but results require clinical interpretation."]
Key facts at a glance
- LOINC
- 82908-5
- Short code
- THF/5A-THF 24h Ur-sRto
- Synonyms
- THF/5A-THF 24h Ur-sRto
- Category
- liver
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures 5-alpha-tetrahydrocortisol and total tetrahydrocortisol in urine collected for 24 hours. The results may be expressed as a ratio to show how these cortisol metabolites relate to one another.
Why might I need this test?
It may be used in the evaluation of disorders involving cortisol or androgen metabolism, including suspected problems with steroid-metabolizing enzymes. It is generally interpreted with symptoms, other hormone tests, and sometimes genetic testing.
How is the test performed?
You collect all urine for a full 24-hour period in the container provided by the laboratory. The laboratory then measures the steroid metabolites and may calculate the 5-alpha-tetrahydrocortisol-to-tetrahydrocortisol ratio.
How do I prepare for the test?
Follow the laboratory's 24-hour urine collection instructions, including when to start and how to store the container. Tell the healthcare provider about medicines, supplements, pregnancy, or missed collections, because these can affect interpretation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An abnormal ratio may indicate altered activity of enzymes involved in cortisol and androgen metabolism, such as 5-alpha-reductase or 11-beta-hydroxysteroid dehydrogenase. The finding does not identify a specific disorder by itself and must be interpreted alongside the clinical evaluation and other laboratory results.
Short name
5α-THF/THF Ratio, 24-Hour Urine
Frequently asked questions
Do I need to fast for this test?
What happens if I miss part of the 24-hour urine collection?
Does an abnormal result mean I have a hormone disorder?
Sources
- 1
- 2Lab Tests OnlineSource
- 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 16, 2026. · Read our editorial policy