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5-Alpha-Tetrahydrocortisol/Tetrahydrocortisol Ratio, Urine

Published: August 9, 2026Updated: August 16, 2026

This urine steroid-metabolite ratio helps assess adrenal cortisol production and may support evaluation for certain forms of congenital adrenal hyperplasia.

Quick summary

["An abnormal ratio can indicate altered adrenal steroid production, including some forms of congenital adrenal hyperplasia."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
82909-3
Short code
THF/5A-THF Ur-sRto
Synonyms
THF/5A-THF 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 the relative amounts of 5-alpha-tetrahydrocortisol and tetrahydrocortisol in urine. These are metabolites formed as the body breaks down cortisol.

Why might I need this test?

It may be ordered as part of an adrenal steroid evaluation, particularly when symptoms or laboratory findings suggest congenital adrenal hyperplasia, a group of inherited conditions affecting steroid production.

How is the test performed?

A urine specimen is analyzed in the laboratory to determine the ratio of 5-alpha-tetrahydrocortisol to tetrahydrocortisol. The collection may be a single urine sample or part of a timed collection, depending on the laboratory's instructions.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional, including whether a first-morning or 24-hour urine sample is required. Medication, illness, and changes in adrenal hormone production can affect results, so tell the laboratory about relevant medicines and health history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher or lower ratio can reflect changes in adrenal steroid metabolism. An elevated ratio may occur with certain forms of congenital adrenal hyperplasia, especially 21-hydroxylase deficiency, but results must be interpreted with symptoms, other steroid measurements, and clinical findings.

Short name

Urinary 5α-THF/THF ratio

Frequently asked questions

What does the 5α-THF/THF ratio measure?
It compares two urinary cortisol metabolites: 5-alpha-tetrahydrocortisol and tetrahydrocortisol. The comparison provides information about how adrenal steroid production is being processed.
Is this the same as a urine cortisol test?
No. A urine cortisol test measures cortisol itself, while this test measures the relationship between two cortisol metabolites. They may be ordered together as part of an adrenal assessment.
Does an abnormal result confirm a specific disorder?
No. An abnormal ratio can support suspicion of an adrenal steroid disorder, but it does not establish a diagnosis by itself. Your clinician will interpret it alongside other laboratory results and your medical history.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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