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Cortisol, Serum (12 PM) – 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 at 12 PM. Cortisol helps regulate metabolism, immune response, and stress reactions.

Quick summary

["Assesses your body’s cortisol levels at a specific time for diagnosing conditions like adrenal insufficiency or Cushing’s syndrome."]

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

Key facts at a glance

LOINC
48099-6
Short code
Cortis 12 PM SerPl-mCnc
Synonyms
Cortis 12 PM 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 this test if you have symptoms like fatigue, weight changes, or unexplained stress that could be linked to hormonal imbalances. It helps evaluate conditions affecting cortisol production or metabolism, such as Addison’s disease or Cushing’s syndrome.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test to ensure accurate results. Bring your medications and any recent changes in symptoms to your doctor’s visit.

How the Test Is Performed

A healthcare provider will draw blood from a vein in your arm. The blood sample will be sent to a lab for analysis to measure cortisol concentration.

Possible Results and Interpretation

Results are compared to reference ranges specific to your age, sex, and health status. Low cortisol levels may indicate adrenal gland issues, while high levels could suggest overproduction or other conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Cortisol is crucial for managing stress and maintaining balance in your body. Abnormal levels can cause symptoms like extreme tiredness, muscle weakness, or changes in blood pressure. This test helps diagnose conditions that affect cortisol production or function, such as adrenal insufficiency or Cushing’s disease.

Short name

Morning cortisol level

Frequently asked questions

What does a low cortisol level mean?
A low cortisol level may suggest adrenal gland problems, such as Addison’s disease, where the glands don’t produce enough cortisol. It can also occur due to other health conditions or medications. Your doctor will discuss further testing or treatments based on your symptoms and results.
What does a high cortisol level mean?
High cortisol levels may indicate conditions like Cushing’s syndrome, where the body produces too much cortisol. This can be caused by tumors, certain medications, or prolonged stress. Your doctor will review your medical history and other test results to determine the cause.
Can lifestyle changes affect cortisol levels?
Yes, lifestyle factors like sleep quality, stress levels, and diet can influence cortisol. Poor sleep, chronic stress, or an unhealthy diet may temporarily raise cortisol. Avoiding caffeine, alcohol, and excessive stress before the test can help ensure more accurate results.
  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