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Cortisol, Serum (Mass Concentration)

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

This test measures the amount of cortisol, a natural steroid hormone produced by your adrenal glands, in your blood serum.

Quick summary

["Cortisol helps regulate stress responses, metabolism, and immune function."]

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

Key facts at a glance

LOINC
58824-4
Short code
Cortis sp19 SerPl-mCnc
Synonyms
Cortis sp19 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 This Test Might Be Ordered

Your healthcare provider may recommend this test to evaluate adrenal gland function, diagnose conditions like Cushing’s syndrome or Addison’s disease, or assess how your body responds to stress or medications.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8 hours before the blood draw if cortisol levels are being measured at specific times (e.g., morning or evening).

How the Test Works

A blood sample is taken from a vein, usually in your arm. The sample is then analyzed to measure cortisol levels using a sensitive laboratory method.

What the Results Mean

Results help determine whether cortisol levels are too high or too low, which can indicate underlying health issues. Your provider will interpret the results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Cortisol

Frequently asked questions

What causes cortisol levels to be tested?
Cortisol levels may be tested if you have symptoms like unexplained weight changes, fatigue, high blood pressure, or signs of hormonal imbalances. It may also be used to evaluate responses to stress, medications, or adrenal gland disorders.
How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time.
Can I take anything before the blood draw?
If fasting is required, avoid eating or drinking anything except water for the specified period (usually 8 hours). If no fasting is needed, follow your provider’s instructions for any medications or activities to avoid.
  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