Cortisol (serum/plasma) concentration, measured by immunoassay
This test measures the amount of cortisol, a hormone produced by your adrenal glands, in your blood. Cortisol helps regulate metabolism, immune response, and stress reactions.
["Cortisol helps manage stress and supports normal bodily functions."]
Key facts at a glance
- LOINC
- 1401-9
- Short code
- Cortis 1h p 250 ug ACTH rIM SerPl-mCnc
- Synonyms
- Cortis 1h p 250 ug ACTH rIM SerPl-mCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 60
- 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 Might You Need This Test?
Your doctor may order this test to check for conditions like Cushing’s syndrome (too much cortisol), adrenal insufficiency (too little cortisol), or to monitor treatment for hormone-related disorders. It can also help diagnose issues with stress responses or hormone imbalances.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if cortisol levels are being checked at specific times of day. Tell your doctor about any medications, supplements, or recent stress that could affect results.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. The sample is sent to a lab for analysis using an immunoassay method to detect cortisol levels accurately.
What Do Results Mean?
Results help determine whether your cortisol levels are within normal ranges or if further evaluation is needed. Abnormal results may prompt additional testing, such as a 24-hour urine collection or multiple blood tests over time.
Reference range
NCBI: ACTH 10-60 pg/mLN/A
Typically collected in the morning (8-10 AM). Inform your provider if taking steroid medications.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Cortisol plays a key role in managing stress, immune function, and metabolism. Low levels may indicate adrenal gland problems, while high levels could signal conditions like Cushing’s syndrome or chronic stress. Your doctor will interpret results in the context of your symptoms and medical history.
Short name
Cortisol Level
Frequently asked questions
Why was cortisol tested?
What if my results are abnormal?
Can diet or stress affect cortisol test results?
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 17, 2026. · Read our editorial policy