Cortisol, Salivary, Free, 24-Hour Composite (Total)
This test measures the total amount of cortisol, a natural steroid hormone, in your saliva over a 24-hour period. Cortisol helps regulate metabolism, immune response, and stress reactions.
["Helps assess your body’s cortisol levels over time for diagnosing conditions like adrenal insufficiency or Cushing’s syndrome."]
Key facts at a glance
- LOINC
- 58647-9
- Short code
- Cortis sp12 p chal Sal-sCnc
- Synonyms
- Cortis sp12 p chal Sal-sCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Salivary cortisol testing is often used because cortisol levels in saliva reflect your body’s natural circadian rhythm and stress response more accurately than blood tests alone. This method avoids the variability caused by fasting or blood draw stress.
What to Expect Before the Test
You’ll collect saliva samples throughout the day (typically every few hours) in a provided container. The test may require a kit sent to your home or a clinic visit for collection. Follow the instructions carefully to ensure accurate results.
How the Test Works
Saliva is collected in a sterile container, and the total cortisol content is measured using a sensitive immunoassay method. The samples are then analyzed to provide a composite 24-hour total cortisol value.
Clinical Uses
This test helps diagnose conditions such as adrenal insufficiency (e.g., Addison’s disease), Cushing’s syndrome, or evaluate chronic stress-related cortisol dysregulation. It can also be used to monitor treatment responses in patients on cortisol-replacement therapy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: Salivary cortisol testing is particularly useful for detecting abnormal cortisol patterns that may not be captured by single blood draws. Low levels may indicate adrenal insufficiency, while elevated levels may suggest hypercortisolism or other hormonal imbalances. This method reduces the impact of circadian fluctuations and stress on results, offering a more reliable long-term assessment of cortisol function.
Short name
Salivary Cortisol (24-hour)
Frequently asked questions
Why do doctors order a 24-hour salivary cortisol test?
What should I do to prepare for this test?
Will the results affect my treatment?
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