Cortisol (Serum or Plasma) Measurement
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 checks your levels for health assessment or diagnosis."]
Key facts at a glance
- LOINC
- 34065-3
- Short code
- Cortis pre/p ACTH SerPl-sCnc
- Synonyms
- Cortis pre/p ACTH SerPl-sCnc
- 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 This Test Is Done
Doctors may order cortisol testing to diagnose conditions like Cushing’s syndrome (too much cortisol), Addison’s disease (too little cortisol), or to evaluate stress-related symptoms. It can also be used in research or specialized studies involving hormone function.
What to Expect Before the Test
No special preparation is needed unless instructed by your healthcare provider. You may be asked to fast or avoid certain medications for a specified time before the blood draw. Bring your test list if prescribed medications are involved.
During the Test
A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood sample will be sent to a lab for analysis.
After the Test
You can resume normal activities immediately. Apply gentle pressure to the site to stop any bleeding, and check the area for bruising or swelling. Report any unusual symptoms like excessive pain or swelling to 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.
Abnormal cortisol levels can indicate hormonal imbalances, such as overproduction (e.g., Cushing’s syndrome) or underproduction (e.g., Addison’s disease). Chronic stress, certain medications, or medical conditions like tumors may also affect cortisol levels. Regular monitoring helps manage conditions like diabetes, hypertension, or autoimmune disorders.
Short name
Cortisol Level
Frequently asked questions
How long does it take to get the results?
What does a low cortisol level mean?
Can I eat or drink before this 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