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Cortisol, Serum (Mass Concentration)

Published: August 9, 2026Updated: August 17, 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 supports normal bodily functions, and this test helps doctors assess hormone balance or potential adrenal issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
1408-4
Short code
Cortis 1D p 40 ug ACTH IM SerPl-mCnc
Synonyms
Cortis 1D p 40 ug ACTH IM SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
60
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 cortisol testing to diagnose conditions like Cushing’s syndrome (too much cortisol), Addison’s disease (too little cortisol), or to evaluate symptoms of adrenal dysfunction, such as fatigue, weight changes, or unexplained stress responses.

What to Expect Before the Test

No special preparation is usually needed, but if your doctor suggests timing (e.g., morning/evening samples), follow their instructions. Avoid caffeine or stress before testing if advised.

What Happens During the Test?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab for analysis using a sensitive immunoassay method to measure cortisol concentration.

What Do Results Mean?

Results may indicate whether cortisol levels are too high or too low, helping pinpoint whether hormonal imbalances are affecting your health. Your doctor will interpret results in relation to your symptoms and medical history.

Reference range

NCBI: ACTH 10-60 pg/mLN/A

Specimen: serum

Typically collected in the morning (8-10 AM). Inform your provider if taking steroid medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Cortisol plays a vital role in stress response, immune function, and metabolism. Abnormal levels can signal adrenal disorders, chronic stress, or other systemic conditions requiring medical evaluation.

Short name

Cortisol Level

Frequently asked questions

Will I feel any discomfort?
You may feel slight pain or a pinch during the blood draw, but it’s usually brief. Most people recover quickly with minimal discomfort.
How long will I wait for results?
Results are typically available within 1–3 business days, depending on lab processing times. Your doctor will contact you with findings.
Can I take anything before or after the test?
Avoid caffeine or heavy meals 1–2 hours before testing if instructed. Afterward, you can resume normal activities unless your doctor advises otherwise.
  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 17, 2026. · Read our editorial policy