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Hormones

Cortisol Test

Cortisol is the body's primary stress hormone, produced by the adrenal glands. It regulates metabolism, immune responses, and the sleep-wake cycle. Levels follow a natural daily rhythm, peaking in the morning and declining throughout the day.

Turnaround up to 72 hours, estimate Turnaround: up to 72 hours after your blood draw (estimate).

We advise against this test

We advise against measuring cortisol if your question is about stress, burnout, fatigue or weight gain. Cortisol fluctuates so much that your value has to roughly double before any change is detectable, and the contraceptive pill, pregnancy, night shifts and even the stress of the blood draw itself shift the result. If your doctor requested this measurement, have your blood drawn between 06:00 and 10:00 in the morning. Read why we advise against this test.

Reference Ranges

See the value that applies to you:

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Male Your group
nmol/l
Low 133 Normal 537 High
Female Your group
nmol/l
Low 133 Normal 537 High

Reference values can vary between laboratories. Discuss your results with your GP for explanation and treatment decisions.

Cortisol: what this test measures

This test measures the concentration of cortisol in your blood, reflecting adrenal gland function and your body's current stress response. Morning samples provide the most clinically meaningful results.

Cortisol: why this value matters

Cortisol imbalances may indicate adrenal dysfunction or chronic stress. Persistently elevated levels could suggest increased cardiovascular and metabolic risk. Low levels may point to adrenal insufficiency. Consult your healthcare provider for interpretation.

Cortisol: how the blood test works

Referral
No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
The draw
A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
Results
Turnaround: up to 72 hours after your blood draw (estimate).
Where
650+ draw sites run by independent laboratories across the Netherlands. Draw sites

Cortisol: how to prepare

  1. Pause biotin

    Required

    Do you take a supplement with biotin (vitamin B8, common in hair, skin and nail supplements)? Stop it 72 hours before the draw. Biotin interferes with the measurement of these values.

  2. Have the draw in the morning

    Required

    These values vary over the day and peak in the morning. Have your blood drawn before 10:00, ideally between 07:00 and 09:00.

  • Water is always fine. Drink as usual beforehand, it makes the draw easier.
  • Take your usual medication, unless your own doctor told you otherwise.

Cortisol: when is testing worthwhile?

Testing may be recommended when experiencing symptoms of chronic stress, fatigue, unexplained weight changes, or sleep disturbances. Morning blood draws provide the most reliable baseline measurement.

Cortisol: symptoms of a high or low value

Low Levels

Some people may experience persistent fatigue, dizziness, muscle weakness, or unexplained weight loss when cortisol levels are low. These symptoms could suggest adrenal insufficiency and warrant medical evaluation.

High Levels

Some people may experience weight gain around the midsection, difficulty sleeping, elevated blood pressure, or mood changes when cortisol levels are persistently elevated. Discuss these symptoms with your healthcare provider.

Cortisol: what to do about an abnormal value

Male

If Low

Low cortisol may indicate adrenal insufficiency. Seek immediate medical attention if experiencing fatigue, weakness, or low blood pressure.

If High

High cortisol may indicate Cushing's syndrome, chronic stress, or depression. Consider stress management, sleep optimization, and endocrine evaluation.

Female

If Low

Low cortisol may indicate adrenal insufficiency. Seek immediate medical attention if experiencing fatigue, weakness, or low blood pressure.

If High

High cortisol may indicate Cushing's syndrome, chronic stress, or depression. Consider stress management, sleep optimization, and endocrine evaluation.

Cortisol: lifestyle and this value

Regular physical activity, consistent sleep schedules, and stress management techniques such as mindfulness or breathing exercises may help support healthy cortisol patterns. Reducing caffeine intake in the afternoon could also be beneficial.

Cortisol: frequently asked questions

When should cortisol be tested?

Morning blood draws are preferred, as cortisol peaks shortly after waking. Your healthcare provider can advise on optimal timing.

Can stress affect my cortisol result?

Yes, acute stress or anxiety before the test may temporarily elevate cortisol. Try to remain calm before your blood draw.

What causes high cortisol levels?

Chronic stress, certain medications, and adrenal conditions may contribute. Your healthcare provider can help determine the underlying cause.

Tests with related values

These panels measure values from the same category as this marker.

Results without a doctor's assessment

You receive your values with the unit and reference range. A doctor's assessment is not part of this site. Discuss your results with your GP for explanation and treatment decisions.

Cortisol

€29,-