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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. Cortisol plays a key role in managing stress responses, metabolism, and immune function.

Quick summary

["Cortisol helps regulate your body’s response to stress and supports normal daily functions."]

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

Key facts at a glance

LOINC
58826-9
Short code
Cortis sp17 SerPl-mCnc
Synonyms
Cortis sp17 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 a serum cortisol test to evaluate adrenal gland function, diagnose conditions like Cushing’s syndrome (overproduction of cortisol) or Addison’s disease (underproduction), or assess stress-related hormone imbalances. It may also be used to monitor treatment for conditions affecting cortisol levels.

What to Expect Before the Test

No special preparation is typically needed, but you may be asked to avoid certain medications (like steroids) that could affect results. If you’re taking them, always inform your provider. You can eat and drink normally unless instructed otherwise.

What Happens During the Test

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are usually reported as a mass concentration of cortisol in your blood. Your provider will interpret these results in the context of your symptoms, medical history, and other tests. Abnormal levels may indicate hormonal imbalances that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Cortisol

Frequently asked questions

What Are Common Causes of Abnormal Results?
Elevated cortisol levels may be linked to conditions like Cushing’s syndrome (due to excess hormone production), prolonged stress, or certain medications. Low cortisol levels could suggest Addison’s disease, adrenal insufficiency, or other adrenal or pituitary disorders. Always discuss results with your provider for personalized insights.
How Often Should I Get This Test?
The frequency depends on your symptoms, diagnosis, or treatment plan. Your provider will determine if repeat testing is needed—this could be monthly, yearly, or as part of ongoing monitoring for chronic conditions.
Can I Take Anything Before or After the Test?
Avoid taking medications that affect cortisol levels (like steroids) without consulting your provider. If you’re unsure, check with them. After the test, you can resume your normal activities, but avoid strenuous exercise that might temporarily alter cortisol levels.
  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