Cortisol, Serum, Late Morning (4 PM)
This test measures your cortisol hormone level in your blood at 4:00 PM to assess your body’s ability to produce cortisol, which helps regulate stress responses and metabolism.
["Cortisol helps manage stress and keeps your body functioning properly—this test checks if your levels are within expected ranges."]
Key facts at a glance
- LOINC
- 45049-4
- Short code
- Cortis 4 PM SerPl-sCnc
- Synonyms
- Cortis 4 PM 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 Is Done
Your doctor may order this test if they suspect conditions like Cushing’s syndrome (too much cortisol), adrenal insufficiency (too little cortisol), or to evaluate how your body responds to stress or medications that affect cortisol levels. It can also help diagnose or monitor conditions like pituitary tumors or chronic stress-related 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 blood draw to ensure accurate results. Avoid caffeine or stress-inducing activities for a few hours before testing.
How the Test Works
A healthcare provider will draw blood from a vein in your arm. The sample is sent to a lab where cortisol is measured using a sensitive immunoassay method to detect its presence in your serum.
What the Results Mean
Results are compared to general reference ranges, but individual ranges can vary based on age, health status, and other factors. High cortisol levels may indicate overproduction, while low levels could signal adrenal problems or medication effects.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated cortisol levels may suggest conditions like Cushing’s syndrome, excessive stress, or certain tumors affecting the adrenal glands or pituitary. Low cortisol levels could indicate adrenal insufficiency, autoimmune disorders, or prolonged steroid use. Monitoring cortisol helps guide treatment for managing these conditions effectively.
Short name
Cortisol Level
Frequently asked questions
What causes abnormal cortisol levels?
How long does it take to get results?
Can I take anything before the 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 16, 2026. · Read our editorial policy