Cortisol, Serum or 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."]
Key facts at a glance
- LOINC
- 47851-1
- Short code
- Cortis p Dex SerPl-mCnc
- Synonyms
- Cortis p Dex 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 Is This Test Done?
Your doctor may order cortisol testing to check for conditions like Cushing’s syndrome (overactive adrenal glands), Addison’s disease (underactive adrenal glands), or to evaluate stress responses, especially if symptoms like weight changes, fatigue, or unusual mood swings are present.
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 draw if timing your cortisol levels around a specific time of day (e.g., morning or evening). Bring any medications you’re taking to your appointment.
What Happens During the Test
A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it typically only takes a few minutes. The sample is sent to a lab for analysis.
What to Expect After the Test
You can return to your normal activities immediately. There may be mild bruising or soreness at the injection site, but this usually fades within a day or two.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal cortisol levels can indicate hormonal imbalances. High cortisol may suggest conditions like Cushing’s syndrome, while low levels could point to Addison’s disease or other adrenal dysfunctions. Your doctor may also use cortisol testing to monitor treatment progress for these conditions or other stress-related disorders.
Short name
Cortisol Level
Frequently asked questions
What does cortisol testing involve?
How long does it take to get results?
Can I take my medications before the 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