Cortisol in Saliva (Free Cortisol, 24-Hour Average)
This test measures the amount of cortisol, a natural steroid hormone produced by your adrenal glands, in your saliva over a 24-hour period. It helps assess your body’s cortisol levels, which can be important for diagnosing conditions related to stress, hormone imbalances, or adrenal function.
["This test helps evaluate your body’s natural cortisol production and response to stress over time."]
Key facts at a glance
- LOINC
- 58637-0
- Short code
- Cortis sp10 p chal Sal-mCnc
- Synonyms
- Cortis sp10 p chal Sal-mCnc
- 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 Is Done
Your doctor may recommend this test if they suspect conditions like Cushing’s syndrome (too much cortisol), Addison’s disease (too little cortisol), or other hormonal or stress-related disorders. It can also be used to monitor treatment effectiveness for conditions affecting cortisol levels.
What to Expect Before the Test
No special preparation is needed. You’ll collect saliva samples throughout the day, typically in the morning and evening, using a collection device provided by your lab. Follow the instructions carefully to ensure accurate results.
How the Test Works
Saliva contains cortisol, which is measured using a specialized immunoassay method. The test captures your natural cortisol fluctuations over 24 hours, giving a more comprehensive picture than a single blood or urine sample.
What the Results Mean
Results are compared to reference ranges for healthy adults, though individual variations exist. Abnormally high or low levels may indicate underlying health concerns that require further evaluation by your healthcare provider.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Cortisol plays a key role in managing stress, immune response, and metabolism. Abnormal levels can signal conditions like adrenal insufficiency, Cushing’s syndrome, or pituitary disorders. This test helps diagnose and monitor these conditions by providing a full-day snapshot of cortisol production.
Short name
Salivary Cortisol (24-Hour)
Frequently asked questions
What causes abnormal cortisol levels in this test?
How often should I get this test?
Can diet or lifestyle affect this test?
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