What is this test?
Cortisol is the stress hormone produced by the adrenal glands. Because it fluctuates during the day, it is usually measured in the morning. It is used to investigate hormonal disorders such as adrenal insufficiency and Cushing's syndrome.
When is it requested?
Cortisol is the primary glucocorticoid hormone synthesized and secreted by the adrenal cortex. Cortisol is vital: it regulates carbohydrate, protein, and lipid metabolism, maintains normal blood pressure, and inhibits allergic and inflammatory reactions. Circulating cortisol levels follow a diurnal pattern in healthy individuals.
What does a high Cortisol result mean?
Cortisol is highest in the morning and lowest at night; stress and poor sleep raise it. A single high value does not mean Cushing's syndrome.
- Stress, pain or anxiety during the blood draw
- Lack of sleep, night shifts or intense exercise
- Pregnancy and birth control pills (increased carrier protein)
- Acute illness, surgery or severe infection
- Corticosteroid medicines (tablets, creams, inhalers or injections)
- Depression or heavy alcohol use
- Cushing's syndrome (pituitary or adrenal origin)
What does a low Cortisol result mean?
Low cortisol is normal in afternoon or evening samples; a low morning value should be investigated for adrenal insufficiency.
- Blood drawn in the afternoon or evening
- Stopping or reducing long-term corticosteroid treatment
- Certain antifungal and seizure medicines
- Underactive pituitary gland (ACTH deficiency)
- Adrenal insufficiency (Addison's disease)
My result is outside the reference range. What should I do?
Cortisol blood is usually drawn early in the morning (between 08:30 and 10:30), when rested. Tell your doctor about steroid creams, inhalers and tablets; abnormal results are usually confirmed with stimulation or suppression tests.
Reference ranges depend on the method, age and sex; always use the range printed on your report. This information is for general guidance only; consult your doctor for diagnosis and treatment.
Sample information
- Sample type: Serum
- Tube / container: Yellow-top tube
- Sample volume: 1 mL
Preparation
Serum (Sample must be collected fasting between 08:00-10:00 or 16:00-18:00. The collection time must be written on the tube.)
Testing and results
- Method: CLIA
- Run schedule: Daily
- Turnaround time: 4 hours
Price and appointment
Add the test to your list to receive a price quote by e-mail, or call +90 850 640 07 30 / message us on WhatsApp (+90 537 301 22 14). You can have the test done at our branches or with our home blood collection service. Results can be viewed online with your Turkish ID number (or passport number for foreign nationals).