Cortisol, Serum (Mass Concentration)
This test measures the amount of cortisol, a natural steroid hormone produced by your adrenal glands, in your blood serum.
["Cortisol helps regulate metabolism, immune response, and stress reactions."]
Key facts at a glance
- LOINC
- 108145-4
- Short code
- Cortis sp5 SerPl-sCnc
- Synonyms
- Cortis sp5 SerPl-sCnc
- 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 a cortisol test to diagnose or monitor conditions such as adrenal gland disorders (e.g., Cushing’s syndrome or Addison’s disease), evaluate stress responses, or check for hormonal imbalances. It can also help assess whether medications are affecting cortisol levels.
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 timing your cortisol levels around certain times of the day is important. If you’re taking medications that affect cortisol, inform your provider beforehand.
How the Test Is Performed
A blood sample is drawn from a vein, typically in your arm. The sample is then sent to a lab for analysis using a sensitive immunoassay method to measure cortisol concentration.
What the Results Mean
Cortisol levels can vary throughout the day, peaking in the morning and dropping at night. Results may be interpreted in relation to your symptoms, medical history, and timing of the sample. Your provider will discuss the meaning of your specific results with you.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Serum Cortisol
Frequently asked questions
High cortisol levels may indicate conditions like Cushing’s syndrome, chronic stress, or certain tumors. Low cortisol levels could signal adrenal insufficiency, pituitary disorders, or other hormonal imbalances. Regular monitoring may be needed if you have ongoing symptoms or conditions requiring long-term management.
Cortisol helps your body respond to stress, supports metabolism, and maintains blood pressure. It also plays a role in immune function and inflammation regulation. If your levels are consistently too high or too low, it may affect your energy, mood, or overall health.
Can diet or medications affect cortisol test results?
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