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
- 1451-4
- Short code
- Cortis pre Ins IV SerPl-mCnc
- Synonyms
- Cortis pre Ins IV 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 check for conditions like Cushing’s syndrome (too much cortisol), adrenal insufficiency (too little cortisol), or to monitor treatment for hormone-related disorders. It can also help diagnose issues with stress responses or hormonal imbalances.
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 test if cortisol levels are being checked at specific times of the day. Your blood will be drawn from a vein in your arm.
What Happens During the Test
A healthcare professional will insert a small needle into your arm to draw blood. You may feel a brief pinch, but it’s usually over quickly. The blood sample will be sent to a lab for analysis.
What the Results Mean
Results are interpreted by your provider based on your symptoms, medical history, and other test results. Abnormally high or low cortisol levels may indicate underlying health concerns that need further evaluation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cortisol levels are critical for managing stress, immune function, and metabolism. Chronic high cortisol (e.g., from prolonged stress or Cushing’s syndrome) can lead to weight gain, fatigue, or weakened bones. Chronic low cortisol (e.g., adrenal insufficiency) may cause dizziness, low blood pressure, or weakness. Your provider will use these results to guide treatment or further testing if needed.
Short name
Cortisol Level
Frequently asked questions
How long does it take to get my cortisol test results?
Can I eat or drink before this test?
What are common reasons for abnormal cortisol levels?
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