Cortisol, Serum (Early Morning)
This test measures the amount of cortisol, a natural steroid hormone produced by your adrenal glands, in your blood at a specific time in the morning. It helps assess adrenal function and can identify conditions like Cushing’s syndrome or adrenal insufficiency.
["Your morning cortisol levels can signal whether your adrenal glands are working properly."]
Key facts at a glance
- LOINC
- 50433-2
- Short code
- Cortis 3 AM SerPl-mCnc
- Synonyms
- Cortis 3 AM 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 Is This Test Done?
Your doctor may order this test if they suspect conditions affecting your adrenal glands, such as Cushing’s syndrome (too much cortisol) or Addison’s disease (too little cortisol). It can also be used to evaluate stress responses or monitor treatment for hormone-related disorders.
What to Expect Before the Test
No special preparation is needed, but you should fast for 8–12 hours before the test (if instructed). Bring your morning urine sample if your doctor has asked for a 24-hour collection. Avoid caffeine or alcohol before testing.
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. Results are typically available within 1–3 business days.
What Do Results Mean?
High cortisol levels may indicate conditions like Cushing’s syndrome, while low levels could suggest adrenal insufficiency or other stress-related issues. Your doctor will interpret results in the context of your symptoms and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cortisol is critical for regulating metabolism, immune response, and stress reactions. Abnormal levels can cause fatigue, weight changes, or hormonal imbalances. This test helps diagnose or monitor adrenal disorders by measuring cortisol at a key time of day.
Short name
Morning Cortisol
Frequently asked questions
Why is morning cortisol testing important?
What if I miss my morning appointment?
Can diet or medications affect 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