Cortisol (serum/plasma, mass concentration)
This test measures the amount of cortisol, a natural steroid 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, and this test helps doctors assess adrenal gland health or hormone imbalances.
Key facts at a glance
- LOINC
- 58631-3
- Short code
- Cortis 1.5h p 1 ug/kg CRH IV Sal-mCnc
- Synonyms
- Cortis 1.5h p 1 ug/kg CRH IV 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
- CPT
- 86701
- 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 if you have symptoms like unexplained weight changes, fatigue, muscle weakness, or changes in your menstrual cycle. It could also be used to diagnose conditions such as Cushing’s syndrome, Addison’s disease, or adrenal insufficiency, or to evaluate stress-related hormone levels.
What to Expect Before the Test
No special preparation is needed for this blood test. You may be asked to fast for 8–12 hours before the draw, but always follow your provider’s instructions. If you’re taking medications that affect cortisol levels, let your lab staff know.
How the Test Is Performed
A healthcare professional will draw blood from a vein in your arm using a small needle. The blood sample will be sent to a lab for analysis. Cortisol is measured in the serum or plasma portion of your blood.
What the Results Mean
Results are typically reported as a mass concentration (e.g., micrograms per deciliter or nanograms per milliliter). Your provider will compare these results to standard reference ranges to determine if your cortisol levels are within normal limits or if further evaluation is needed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormally high cortisol levels may indicate conditions like Cushing’s syndrome, where the body produces too much cortisol, or chronic stress. Low cortisol levels could signal Addison’s disease, where the adrenal glands don’t produce enough hormones. These imbalances can affect energy, blood pressure, and immune function, so early diagnosis is important.
Short name
Cortisol Level
Frequently asked questions
How long does it take to get my results?
Can I eat or drink before the test?
Will I need to take any special steps if I’m on medication?
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