Cortisol, Serum (Mass Concentration)
This test measures the amount of cortisol, a natural steroid hormone produced by your adrenal glands, in your blood serum. Cortisol plays a key role in managing stress responses, metabolism, and immune function.
["Cortisol helps regulate how your body responds to stress and supports normal bodily functions."]
Key facts at a glance
- LOINC
- 58828-5
- Short code
- Cortis sp14 SerPl-mCnc
- Synonyms
- Cortis sp14 SerPl-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 Might Be Ordered
Your healthcare provider may recommend this test to evaluate adrenal gland function, diagnose conditions like Cushing’s syndrome or Addison’s disease, or assess how your body handles stress. It can also help monitor treatment for hormone-related disorders.
What to Expect Before the Test
No special preparation is needed, but if you’re taking medications that affect cortisol levels (like steroids), your provider may ask you to stop them temporarily or adjust timing. Avoid caffeine or alcohol for a few hours before testing, as they can influence results.
What Happens During the Test
A blood sample will be drawn from a vein in your arm by a healthcare professional. The sample is sent to a lab for analysis, where cortisol levels are measured using a sensitive detection method.
What the Results Mean
Results help determine whether cortisol levels are too high or too low, which can indicate underlying health issues. Your provider will interpret the results in the context of your symptoms and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cortisol levels are crucial for diagnosing conditions like adrenal insufficiency (too little cortisol) or hyperadrenocorticism (too much cortisol). Abnormal results may prompt further testing, such as a 24-hour urine cortisol collection or a dexamethasone suppression test.
Short name
Serum Cortisol
Frequently asked questions
What causes cortisol levels to be tested?
How long does it take to get the results?
Can diet or lifestyle 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 16, 2026. · Read our editorial policy