Insight into your cortisol level.
Cortisol is a hormone that plays a role in stress, energy, and metabolism, among other things. A morning measurement gives insight into your cortisol level, with personal explanation from our doctors.
Also known as: stress hormone, hydrocortisone
Personal assessment by our BIG-registered Bloodworks® doctors
By the Bloodworks editorial team
Cortisol blood test
- Total
- 69,-
Next step: choose your collection point
- No referral needed
- 1000+ collection points
- Results typically within 2 working days
- Every result reviewed by a BIG-registered doctor
For a broader picture of fatigue
View Extended Fatigue & Sleep
Cortisol is one part of the broader picture of fatigue. This value package also includes thyroid function, ferritin, B12, and vitamin D in a single blood draw.
View package · 219,-How Bloodworks works
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Blood draw
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Securely, typically within 2 working days from our physicians
Background
What is cortisol?
Cortisol is a hormone produced by the adrenal glands and is involved in the stress response, blood sugar regulation, blood pressure, and the immune system. Cortisol has a strong diurnal rhythm: the level is at its highest in the early morning and falls throughout the day.
For a reliable interpretation of a single cortisol measurement, an early morning sample is almost always taken, ideally between 7 and 9 o'clock. Production is controlled by ACTH from the pituitary gland. For specific questions about the pattern of cortisol throughout the day, cortisol curves (multiple measurement points) and salivary cortisol also exist, those measurements are not currently offered by us.
In brief
Adrenal hormone
Produced in the adrenal glands
Strong diurnal rhythm
Highest level in the morning
Stress response
Plays a role in activation
Single cortisol
Standard morning measurement
This marker is also included in
Testing several values in a single draw takes one blood collection and gives a more complete picture. The choice is yours.
Common reasons to test
When can insight into your Cortisol be valuable?
Below are some situations in which measuring Cortisol can provide insight.
Insight into your morning cortisol
A test gives a snapshot of your cortisol at the time of day when the level is at its highest and easiest to interpret, as a baseline or for comparison over time.
With questions about energy and stress
Prolonged tension or unexplained changes in energy are sometimes associated with the stress response. A measurement does not show the cause, but it does provide a factual starting point.
With questions about sleep
The cortisol diurnal rhythm is closely linked to the sleep-wake cycle. If you sleep poorly or irregularly, a morning measurement can serve as a factual starting point; do let us know about an atypical rhythm for the interpretation.
For athletes
Athletes sometimes measure cortisol as part of overtraining monitoring and recovery evaluation. A single value says little on its own; the trend over time, alongside rest and performance, is more informative.
For follow-up of a previous measurement
Those who have previously had a test can repeat it to track the value over time. Have your blood drawn at a similar time in the morning; because of the diurnal rhythm, values are otherwise difficult to compare.
For a general hormonal check
Cortisol is often measured as part of a broader hormonal overview, alongside testosterone or thyroid hormones, for example. That provides context: hormones influence one another and a single value rarely tells the whole story.
What your result means
How do we read your Cortisol level?
Cortisol is measured in nanomoles per litre (nmol/L). Because cortisol has a strong diurnal rhythm, interpretation depends on the time of the blood draw, for the standard measurement, an early morning sample is almost always required.
A low value
A low morning cortisol can have various causes, including certain conditions of the adrenal glands or pituitary gland. Our doctor provides explanation and context for your result.
A normal value
A morning cortisol within the reference range gives a reassuring picture for this moment. For specific questions about the cortisol pattern throughout the day, multiple measurements (a cortisol curve) or salivary cortisol can provide more information than a single blood measurement.
A high value
Elevated cortisol can be a temporary increase (acute stress, illness, intensive exercise) or a more sustained elevation. For persistently elevated values, our doctor provides explanation and context regarding next steps.
How we interpret your result
Our doctors interpret your cortisol against the time of the blood draw and the reference ranges of the laboratory. You receive a report in plain language, as a starting point for your own insight or a conversation with your healthcare provider.
Related tests
Often combined with Cortisol.
A single marker gives one perspective. For a broader picture you can combine Cortisol with a theme package or related markers.
+ 29,- blood draw fee per orderFree from 225,-
Frequently asked questions
Everything you want to know
Do I need to fast for a cortisol test?
Fasting is not required, but we recommend having your blood drawn in the morning between 7 and 9 o'clock, cortisol is at its highest then and most suitable for interpretation.
Why does cortisol need to be measured in the morning?
Cortisol has a pronounced diurnal rhythm: the level is high in the early morning and falls over the course of the day to a low point in the evening. An afternoon or evening value is therefore interpreted differently, and the laboratory's reference ranges also assume a morning sample. A morning measurement, preferably between 7 and 9 o'clock, therefore provides the most reliable baseline.
What if I sleep late or work night shifts?
The cortisol diurnal rhythm follows your sleep-wake cycle. If you work night shifts or consistently get up late, your rhythm may be shifted and a single morning value is more difficult to interpret. Please let us know, then our doctor takes this into account in the interpretation.
Can a cortisol test detect burnout?
No. Burnout is not a diagnosis that can be made or ruled out with a blood test. Cortisol levels of people with burnout complaints largely overlap with those of people without complaints. A measurement can provide a factual starting point, but a normal value does not rule anything out and an abnormal value does not prove anything.
What is the difference with salivary cortisol?
Salivary cortisol can be collected at multiple points throughout the day and thereby gives a picture of the diurnal rhythm. It measures the free, biologically active fraction. We currently measure serum cortisol only.
Does my medication affect my cortisol level?
Yes, it can. Prednisolone-like medicines (corticosteroids) influence the cortisol measurement. The contraceptive pill can also affect the result: the total cortisol level can come out higher because the blood then contains more cortisol-binding protein, without there being more active cortisol. Please always let us know of any medication and pill use, then our doctor takes this into account in the interpretation.
What can an elevated morning cortisol mean?
An elevated morning value often fits with temporary factors, such as stress, lack of sleep, illness, intensive exercise, or tension around the blood draw itself. Medication can also influence the measured value; this applies among others to prednisolone-like medicines (corticosteroids). Only rarely does an elevated value fit with a medical condition. Our doctor provides context for your result and explains when re-testing is worthwhile.
What can a low morning cortisol mean?
A low morning value does not always have a medical cause. Sometimes the explanation is practical, for example a blood draw later in the morning, when the level has already fallen physiologically. Use of corticosteroids can also temporarily suppress the body's own cortisol production; please always let us know about such use.
How often should I measure cortisol?
A single measurement is sufficient for initial insight. For follow-up questions, repeat testing or a more extensive measurement (curve) can be considered.
What do I do with my result?
You will receive a PDF report with your value and explanation. What you do with it, such as discussing it with your GP or taking no action, remains entirely your choice.
Can I share my report with my GP?
Yes, the report is written in medical language and contains all relevant laboratory information.
In the Health Guide
Read more about this value
Where do you give blood?
You can give blood at collection points across the Netherlands, usually without an appointment.
Find a collection point near you or read how a blood draw works.
Want to test multiple markers at once?
Combine Cortisol with other markers via Bloodworks Select. The blood draw and collection fee is charged once per order, and is waived from 225,-.
Ready for insight into your cortisol level?
You receive your cortisol level including personal explanation from a doctor, typically within 2 working days. No referral required.