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Cortisol (Serum) – Mass Concentration

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

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.

Quick summary

["Cortisol helps manage stress and metabolism; abnormal levels may signal adrenal issues or other health concerns."]

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

Key facts at a glance

LOINC
57465-7
Short code
Cortis sp10 SerPl-mCnc
Synonyms
Cortis sp10 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 Is Done

Doctors may order cortisol testing to diagnose conditions like Cushing’s syndrome (too much cortisol), Addison’s disease (too little cortisol), or to evaluate adrenal function during stress, such as surgery or illness. It can also help assess pituitary gland function or rule out hormonal imbalances.

What to Expect Before the Test

No special preparation is needed for this blood test. You may be asked to fast for 8–12 hours before the draw, but confirm with your provider. Stress or certain medications can affect results, so discuss these with your healthcare team.

How the Test Works

A small blood sample is taken 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 mass concentration in the serum.

Possible Results and Next Steps

Results are typically reported as a single value (not a range) and compared to your clinical picture. Elevated cortisol may indicate overproduction (e.g., from tumors or prolonged stress), while low levels could signal adrenal insufficiency or other disorders. Your doctor will interpret results in the context of your symptoms and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Cortisol

Frequently asked questions

What does cortisol measure?
Cortisol measures the concentration of this steroid hormone in your blood. It reflects your body’s current stress response and helps assess adrenal gland function, which can be critical for diagnosing conditions like hormonal imbalances, metabolic disorders, or adrenal-related diseases.
How often should I get this test?
The frequency depends on your symptoms and medical needs. Some patients may need this test once or twice a year, while others with chronic conditions may require more frequent monitoring. Always follow your healthcare provider’s recommendations.
Can lifestyle changes affect cortisol levels?
Yes, lifestyle factors like sleep quality, stress levels, diet, and exercise can influence cortisol. Reducing chronic stress, maintaining a consistent sleep schedule, and eating a balanced diet may help support healthy cortisol levels, but results from this test should be interpreted alongside your overall health status.
  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