Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
Cortisol is highest in the morning and lowest at night, so timing matters. Saliva and urine tests are also used.
Why it's done
- Signs of too much cortisol, like weight gain in the face and belly, purple stretch marks, and high blood sugar
- Signs of too little cortisol, like weakness, weight loss, low blood pressure, and dark skin patches
Getting ready and what happens
- Follow your provider's timing instructions closely.
- Tell your provider about steroid medicines and birth control pills.
How the test is done
- A health worker cleans the skin, puts a band around your arm, and draws blood from a vein with a small needle. It takes a few minutes.
What the results mean
| Result | Typical range for adults |
|---|---|
| Morning blood cortisol | About 5 to 25 mcg/dL (labs vary) |
Normal ranges vary from lab to lab and can differ by age, sex, and pregnancy. Your report lists your lab's own range next to each result. A result a little outside the range is often not a problem.
Low morning cortisol
May point to adrenal insufficiency. More tests, like an ACTH stimulation test, confirm it.
High or lacking the normal nighttime drop
May point to Cushing's syndrome, which needs more testing.
When a result needs quick action
Call 911Known adrenal insufficiency with vomiting, confusion, severe weakness, or fainting (adrenal crisis)
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
- Do I need more tests?
- Could my medicines be affecting results?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related medicines
Sources
Last updated 2026-11-13.