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 maintain balance in your body."]
Key facts at a glance
- LOINC
- 26533-0
- Short code
- Cortis 56h p ACTH SerPl-mCnc
- Synonyms
- Cortis 56h p ACTH 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 This Test Be Done?
Your doctor may order this test to evaluate adrenal gland function, diagnose conditions like Cushing’s syndrome or Addison’s disease, or assess how your body responds to stress or medications. It can also help check for hormonal imbalances or monitor treatment progress for conditions affecting cortisol levels.
What to Expect Before the Test
No special preparation is usually needed, but your doctor might instruct you to fast for 8–12 hours before the test if cortisol is measured at a specific time (e.g., early morning). If you’re taking medications that affect cortisol, let your provider know. Blood is drawn from a vein in your arm.
What Happens During the Test?
A healthcare professional will clean your arm, insert a small needle to draw blood, and collect the sample into a tube. The process takes a few minutes, and you may feel a brief pinch. The blood is then sent to a lab for analysis.
What to Expect After the Test
You can usually return to your normal activities immediately. There may be a small bruise or slight discomfort at the needle site, but these are temporary. If you experience excessive bleeding, swelling, or signs of infection (like redness or fever), contact your doctor.
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.
Abnormally high cortisol levels may indicate conditions such as Cushing’s syndrome (due to excess hormone production) or prolonged stress. Low cortisol levels could suggest Addison’s disease (adrenal insufficiency) or other adrenal disorders. Chronic stress, certain medications, or pregnancy can also influence cortisol levels. Your doctor will interpret results in the context of your symptoms and medical history.
Short name
Cortisol Level
Frequently asked questions
How Long Does It Take to Get Results?
Can Cortisol Levels Change Based on When the Test Is Taken?
Is There Anything I Should Avoid 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 17, 2026. · Read our editorial policy