Cortisol, Serum (Mass Concentration)
This test measures the amount of cortisol, a hormone produced by your adrenal glands, in your blood serum. Cortisol helps regulate metabolism, immune response, and stress reactions.
["Cortisol helps manage stress and keeps your body functioning properly."]
Key facts at a glance
- LOINC
- 1438-1
- Short code
- Cortis 8h p 40 ug ACTH IM SerPl-mCnc
- Synonyms
- Cortis 8h p 40 ug ACTH IM 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 Is This Test Done?
Your doctor may order cortisol testing to diagnose or monitor conditions like Cushing’s syndrome (overactive adrenal glands), Addison’s disease (underactive adrenal glands), or to check for adrenal gland function before surgery or other treatments. It can also help evaluate chronic stress responses or hormone imbalances.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if cortisol is measured at specific times 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. The sample is sent to a lab for analysis. The test typically takes a few minutes, and you may feel slight discomfort but no lasting effects.
What Are Possible Results?
Results are compared to general reference ranges for cortisol, though values can vary based on timing (e.g., morning vs. evening) and individual health. Your doctor will interpret results in the context of your symptoms and medical history.
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 like Cushing’s syndrome, where the body produces too much cortisol, leading to weight gain, fatigue, or high blood pressure. Low cortisol levels could signal Addison’s disease or other adrenal dysfunctions, causing dizziness, weakness, or low blood pressure. Repeated testing may be needed to confirm or track these conditions over time.
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?
Will this test affect my medications?
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