Cortisol
Also written: Cortisol
What it measures
An adrenal hormone that varies strongly with the time of day.
Why it is ordered
Ordered when adrenal function is suspected to be too high or too low.
How to prepare
🔴 The time of the draw determines interpretation — usually early morning. The wrong time means repeating it. Declare all corticosteroid-containing medicines, including creams and inhalers.
Units
µg/dL ↔ nmol/L — convert here
What to ask
- At what time must the sample be taken
- Is an additional dynamic test needed
- Which medicines must I declare
This page does not include reference ranges and does not say whether your number is high or low. Reference ranges differ between laboratories and between people — read yours on your own report, with your clinician.