Cortisol
Your main stress hormone. How it’s tested - blood, saliva or urine - changes what you learn.
TypeBlood · Saliva · Urine
HowBlood in the morning, saliva at set times of day, or a 24-hour urine collection.
How oftenOnly with specific symptoms or when advised.
BeforeTiming is critical - follow instructions exactly. Avoid steroid creams if possible.
WhoPeople with signs of too much or too little cortisol.
One hormone, three very different tests
Cortisol follows a daily rhythm - highest soon after waking, lowest at night. A single number without timing means little.
Blood (morning)
“Is my level too low?”
A single snapshot. Useful to screen for low cortisol (adrenal insufficiency).
Snapshot
Saliva (through the day)
“Is my rhythm off?”
Multiple samples show the daily curve. Late-night saliva helps screen for too much cortisol.
Daily rhythm
Urine (24-hour)
“How much over a whole day?”
Total cortisol output. Used to investigate excess cortisol.
Total output
Is it right for you?
Worth considering if…
- You have signs of excess cortisol - weight gain around the middle, easy bruising, high blood pressure, muscle weakness.
- You have signs of low cortisol - severe fatigue, dizziness, salt cravings, weight loss.
A better option if…
- You feel stressed or tired in general - cortisol tests rarely explain this. Look at sleep, iron, thyroid and B12 first.
- “Adrenal fatigue” panels aren’t a recognised diagnosis.
How it’s measured
Morning serum cortisol
Screens for low cortisol.
Late-night salivary cortisol
Screens for excess cortisol.
24-hour urine free cortisol
Measures total daily output.
Dexamethasone suppression test
A specialist test for excess cortisol.
The full picture
What is it?
A test of cortisol, the body’s main stress hormone.
What type of test is it?
Blood, saliva or urine test.
What does it measure?
Cortisol levels at specific times, or total daily output.
Why might someone consider it?
To investigate suspected cortisol disorders.
Who is it most relevant for?
People with specific symptoms of too much or too little cortisol.
How is it performed?
Depends on sample type - timing is key.
How often might it be considered?
Only when needed.
What can the result help you understand?
Whether cortisol production is abnormal.
What are its limitations?
Stress, sleep, illness, medications and timing all affect results.
What should it be viewed with?
Symptoms, blood pressure, glucose, sleep and medications.
Where to get it
Through your provider
Usually ordered when symptoms or results point to it.
Lab services
e.g. Quest Diagnostics, Labcorp - typically with a provider order.
Specialists
Your provider may refer you to a specialist to interpret it.
Names are examples only, not endorsements. Your provider can often order the same test - and help interpret it.
Connected to
Questions to ask your provider
- Do my symptoms justify a cortisol test?
- Which sample type is right for my question?
Ziva Health
One test is a snapshot. Ziva shows the whole story.
Ziva brings your lab results, wearables and daily readings together - and Isabella tells you what’s changing and what to ask your provider next.
Refer Ziva to my provider / care team
Is your provider not on Ziva yet? Send them a link in under a minute - once they join, they’ll see your Cortisol result alongside your other trends and get alerts directly.
Refer my providerAlready seeing your provider?
Bring your Ziva 30-day report to your next appointment - your Cortisol result and daily trends in one view, so the conversation starts with the full picture.
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Being listed doesn’t mean everyone needs this test. Educational only — not medical advice. Results should be interpreted with a qualified clinician. ← Back to Know What to Test