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Cortisol, Serum (8 AM)

Published: August 9, 2026Updated: August 16, 2026

This test measures cortisol, a hormone produced by your adrenal glands, to check for normal levels at 8 AM. Cortisol helps regulate metabolism, immune response, and stress reactions.

Quick summary

["Assesses adrenal function and stress hormone balance at peak morning levels."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
45051-0
Short code
Cortis 8 PM SerPl-sCnc
Synonyms
Cortis 8 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 you have symptoms like unexplained fatigue, weight changes, or signs of adrenal issues (e.g., high blood pressure, muscle weakness). It’s also used to diagnose conditions like Cushing’s syndrome or adrenal insufficiency.

What to Expect Before the Test

No special preparation is needed, but fasting is typically required. You’ll provide a blood sample drawn early in the morning (around 8 AM) for accuracy.

How the Test Works

A healthcare provider will collect blood from a vein in your arm. The sample is sent to a lab to measure cortisol concentration using an immunoassay method.

Possible Results and Next Steps

Results help determine if cortisol levels are too high or low. Abnormal findings may prompt further testing or treatment adjustments, such as medication or lifestyle changes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Cortisol plays a key role in managing stress and maintaining balance in your body. Low cortisol can lead to fatigue, dizziness, or low blood pressure, while high cortisol may cause weight gain, high blood pressure, or mood changes. Your doctor will interpret results in the context of your symptoms and overall health.

Short name

Morning cortisol level

Frequently asked questions

What causes abnormal cortisol levels?
Abnormal cortisol can result from conditions like Cushing’s syndrome (too much cortisol), adrenal gland disorders (too little), or chronic stress. Other factors, such as certain medications or infections, may also affect results.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss findings with you during a follow-up visit.
Can I eat or drink before the test?
Yes, you can eat a light meal, but avoid caffeine or alcohol before the blood draw. Fasting is required for accuracy, so follow your doctor’s instructions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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